Bug Summary

File:dev/pci/drm/drm_bridge.c
Warning:line 875, column 9
Assigned value is garbage or undefined

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.4 -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name drm_bridge.c -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model static -mframe-pointer=all -relaxed-aliasing -ffp-contract=on -fno-rounding-math -mconstructor-aliases -ffreestanding -mcmodel=kernel -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -target-feature -sse2 -target-feature -sse -target-feature -3dnow -target-feature -mmx -target-feature +save-args -target-feature +retpoline-external-thunk -disable-red-zone -no-implicit-float -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -nostdsysteminc -nobuiltininc -resource-dir /usr/local/llvm16/lib/clang/16 -I /usr/src/sys -I /usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -I /usr/src/sys/arch -I /usr/src/sys/dev/pci/drm/include -I /usr/src/sys/dev/pci/drm/include/uapi -I /usr/src/sys/dev/pci/drm/amd/include/asic_reg -I /usr/src/sys/dev/pci/drm/amd/include -I /usr/src/sys/dev/pci/drm/amd/amdgpu -I /usr/src/sys/dev/pci/drm/amd/display -I /usr/src/sys/dev/pci/drm/amd/display/include -I /usr/src/sys/dev/pci/drm/amd/display/dc -I /usr/src/sys/dev/pci/drm/amd/display/amdgpu_dm -I /usr/src/sys/dev/pci/drm/amd/pm/inc -I /usr/src/sys/dev/pci/drm/amd/pm/legacy-dpm -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/inc -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/smu11 -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/smu12 -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/smu13 -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay/inc -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay/hwmgr -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay/smumgr -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/inc -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/inc/pmfw_if -I /usr/src/sys/dev/pci/drm/amd/display/dc/inc -I /usr/src/sys/dev/pci/drm/amd/display/dc/inc/hw -I /usr/src/sys/dev/pci/drm/amd/display/dc/clk_mgr -I /usr/src/sys/dev/pci/drm/amd/display/modules/inc -I /usr/src/sys/dev/pci/drm/amd/display/modules/hdcp -I /usr/src/sys/dev/pci/drm/amd/display/dmub/inc -I /usr/src/sys/dev/pci/drm/i915 -D DDB -D DIAGNOSTIC -D KTRACE -D ACCOUNTING -D KMEMSTATS -D PTRACE -D POOL_DEBUG -D CRYPTO -D SYSVMSG -D SYSVSEM -D SYSVSHM -D UVM_SWAP_ENCRYPT -D FFS -D FFS2 -D FFS_SOFTUPDATES -D UFS_DIRHASH -D QUOTA -D EXT2FS -D MFS -D NFSCLIENT -D NFSSERVER -D CD9660 -D UDF -D MSDOSFS -D FIFO -D FUSE -D SOCKET_SPLICE -D TCP_ECN -D TCP_SIGNATURE -D INET6 -D IPSEC -D PPP_BSDCOMP -D PPP_DEFLATE -D PIPEX -D MROUTING -D MPLS -D BOOT_CONFIG -D USER_PCICONF -D APERTURE -D MTRR -D NTFS -D SUSPEND -D HIBERNATE -D PCIVERBOSE -D USBVERBOSE -D WSDISPLAY_COMPAT_USL -D WSDISPLAY_COMPAT_RAWKBD -D WSDISPLAY_DEFAULTSCREENS=6 -D X86EMU -D ONEWIREVERBOSE -D MULTIPROCESSOR -D MAXUSERS=80 -D _KERNEL -O2 -Wno-pointer-sign -Wno-address-of-packed-member -Wno-constant-conversion -Wno-unused-but-set-variable -Wno-gnu-folding-constant -fdebug-compilation-dir=/usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fcf-protection=branch -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -o /home/ben/Projects/scan/2024-01-11-110808-61670-1 -x c /usr/src/sys/dev/pci/drm/drm_bridge.c
1/*
2 * Copyright (c) 2014 Samsung Electronics Co., Ltd
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sub license,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the
12 * next paragraph) shall be included in all copies or substantial portions
13 * of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 */
23
24#include <linux/err.h>
25#include <linux/media-bus-format.h>
26#include <linux/module.h>
27#include <linux/mutex.h>
28
29#include <drm/drm_atomic_state_helper.h>
30#include <drm/drm_bridge.h>
31#include <drm/drm_encoder.h>
32#include <drm/drm_of.h>
33#include <drm/drm_print.h>
34
35#include "drm_crtc_internal.h"
36
37/**
38 * DOC: overview
39 *
40 * &struct drm_bridge represents a device that hangs on to an encoder. These are
41 * handy when a regular &drm_encoder entity isn't enough to represent the entire
42 * encoder chain.
43 *
44 * A bridge is always attached to a single &drm_encoder at a time, but can be
45 * either connected to it directly, or through a chain of bridges::
46 *
47 * [ CRTC ---> ] Encoder ---> Bridge A ---> Bridge B
48 *
49 * Here, the output of the encoder feeds to bridge A, and that furthers feeds to
50 * bridge B. Bridge chains can be arbitrarily long, and shall be fully linear:
51 * Chaining multiple bridges to the output of a bridge, or the same bridge to
52 * the output of different bridges, is not supported.
53 *
54 * &drm_bridge, like &drm_panel, aren't &drm_mode_object entities like planes,
55 * CRTCs, encoders or connectors and hence are not visible to userspace. They
56 * just provide additional hooks to get the desired output at the end of the
57 * encoder chain.
58 */
59
60/**
61 * DOC: display driver integration
62 *
63 * Display drivers are responsible for linking encoders with the first bridge
64 * in the chains. This is done by acquiring the appropriate bridge with
65 * devm_drm_of_get_bridge(). Once acquired, the bridge shall be attached to the
66 * encoder with a call to drm_bridge_attach().
67 *
68 * Bridges are responsible for linking themselves with the next bridge in the
69 * chain, if any. This is done the same way as for encoders, with the call to
70 * drm_bridge_attach() occurring in the &drm_bridge_funcs.attach operation.
71 *
72 * Once these links are created, the bridges can participate along with encoder
73 * functions to perform mode validation and fixup (through
74 * drm_bridge_chain_mode_valid() and drm_atomic_bridge_chain_check()), mode
75 * setting (through drm_bridge_chain_mode_set()), enable (through
76 * drm_atomic_bridge_chain_pre_enable() and drm_atomic_bridge_chain_enable())
77 * and disable (through drm_atomic_bridge_chain_disable() and
78 * drm_atomic_bridge_chain_post_disable()). Those functions call the
79 * corresponding operations provided in &drm_bridge_funcs in sequence for all
80 * bridges in the chain.
81 *
82 * For display drivers that use the atomic helpers
83 * drm_atomic_helper_check_modeset(),
84 * drm_atomic_helper_commit_modeset_enables() and
85 * drm_atomic_helper_commit_modeset_disables() (either directly in hand-rolled
86 * commit check and commit tail handlers, or through the higher-level
87 * drm_atomic_helper_check() and drm_atomic_helper_commit_tail() or
88 * drm_atomic_helper_commit_tail_rpm() helpers), this is done transparently and
89 * requires no intervention from the driver. For other drivers, the relevant
90 * DRM bridge chain functions shall be called manually.
91 *
92 * Bridges also participate in implementing the &drm_connector at the end of
93 * the bridge chain. Display drivers may use the drm_bridge_connector_init()
94 * helper to create the &drm_connector, or implement it manually on top of the
95 * connector-related operations exposed by the bridge (see the overview
96 * documentation of bridge operations for more details).
97 */
98
99/**
100 * DOC: special care dsi
101 *
102 * The interaction between the bridges and other frameworks involved in
103 * the probing of the upstream driver and the bridge driver can be
104 * challenging. Indeed, there's multiple cases that needs to be
105 * considered:
106 *
107 * - The upstream driver doesn't use the component framework and isn't a
108 * MIPI-DSI host. In this case, the bridge driver will probe at some
109 * point and the upstream driver should try to probe again by returning
110 * EPROBE_DEFER as long as the bridge driver hasn't probed.
111 *
112 * - The upstream driver doesn't use the component framework, but is a
113 * MIPI-DSI host. The bridge device uses the MIPI-DCS commands to be
114 * controlled. In this case, the bridge device is a child of the
115 * display device and when it will probe it's assured that the display
116 * device (and MIPI-DSI host) is present. The upstream driver will be
117 * assured that the bridge driver is connected between the
118 * &mipi_dsi_host_ops.attach and &mipi_dsi_host_ops.detach operations.
119 * Therefore, it must run mipi_dsi_host_register() in its probe
120 * function, and then run drm_bridge_attach() in its
121 * &mipi_dsi_host_ops.attach hook.
122 *
123 * - The upstream driver uses the component framework and is a MIPI-DSI
124 * host. The bridge device uses the MIPI-DCS commands to be
125 * controlled. This is the same situation than above, and can run
126 * mipi_dsi_host_register() in either its probe or bind hooks.
127 *
128 * - The upstream driver uses the component framework and is a MIPI-DSI
129 * host. The bridge device uses a separate bus (such as I2C) to be
130 * controlled. In this case, there's no correlation between the probe
131 * of the bridge and upstream drivers, so care must be taken to avoid
132 * an endless EPROBE_DEFER loop, with each driver waiting for the
133 * other to probe.
134 *
135 * The ideal pattern to cover the last item (and all the others in the
136 * MIPI-DSI host driver case) is to split the operations like this:
137 *
138 * - The MIPI-DSI host driver must run mipi_dsi_host_register() in its
139 * probe hook. It will make sure that the MIPI-DSI host sticks around,
140 * and that the driver's bind can be called.
141 *
142 * - In its probe hook, the bridge driver must try to find its MIPI-DSI
143 * host, register as a MIPI-DSI device and attach the MIPI-DSI device
144 * to its host. The bridge driver is now functional.
145 *
146 * - In its &struct mipi_dsi_host_ops.attach hook, the MIPI-DSI host can
147 * now add its component. Its bind hook will now be called and since
148 * the bridge driver is attached and registered, we can now look for
149 * and attach it.
150 *
151 * At this point, we're now certain that both the upstream driver and
152 * the bridge driver are functional and we can't have a deadlock-like
153 * situation when probing.
154 */
155
156static DEFINE_MUTEX(bridge_lock)struct rwlock bridge_lock = { 0, "bridge_lock" };
157static DRM_LIST_HEAD(bridge_list)struct list_head bridge_list = { &(bridge_list), &(bridge_list
) };
158
159/**
160 * drm_bridge_add - add the given bridge to the global bridge list
161 *
162 * @bridge: bridge control structure
163 */
164void drm_bridge_add(struct drm_bridge *bridge)
165{
166 rw_init(&bridge->hpd_mutex, "brhpd")_rw_init_flags(&bridge->hpd_mutex, "brhpd", 0, ((void *
)0));
167
168 mutex_lock(&bridge_lock)rw_enter_write(&bridge_lock);
169 list_add_tail(&bridge->list, &bridge_list);
170 mutex_unlock(&bridge_lock)rw_exit_write(&bridge_lock);
171}
172EXPORT_SYMBOL(drm_bridge_add);
173
174#ifdef notyet
175static void drm_bridge_remove_void(void *bridge)
176{
177 drm_bridge_remove(bridge);
178}
179#endif
180
181/**
182 * devm_drm_bridge_add - devm managed version of drm_bridge_add()
183 *
184 * @dev: device to tie the bridge lifetime to
185 * @bridge: bridge control structure
186 *
187 * This is the managed version of drm_bridge_add() which automatically
188 * calls drm_bridge_remove() when @dev is unbound.
189 *
190 * Return: 0 if no error or negative error code.
191 */
192int devm_drm_bridge_add(struct device *dev, struct drm_bridge *bridge)
193{
194 drm_bridge_add(bridge);
195#ifdef notyet
196 return devm_add_action_or_reset(dev, drm_bridge_remove_void, bridge);
197#else
198 STUB()do { printf("%s: stub\n", __func__); } while(0);
199 return -ENOSYS78;
200#endif
201}
202EXPORT_SYMBOL(devm_drm_bridge_add);
203
204/**
205 * drm_bridge_remove - remove the given bridge from the global bridge list
206 *
207 * @bridge: bridge control structure
208 */
209void drm_bridge_remove(struct drm_bridge *bridge)
210{
211 mutex_lock(&bridge_lock)rw_enter_write(&bridge_lock);
212 list_del_init(&bridge->list);
213 mutex_unlock(&bridge_lock)rw_exit_write(&bridge_lock);
214
215 mutex_destroy(&bridge->hpd_mutex);
216}
217EXPORT_SYMBOL(drm_bridge_remove);
218
219static struct drm_private_state *
220drm_bridge_atomic_duplicate_priv_state(struct drm_private_obj *obj)
221{
222 struct drm_bridge *bridge = drm_priv_to_bridge(obj);
223 struct drm_bridge_state *state;
224
225 state = bridge->funcs->atomic_duplicate_state(bridge);
226 return state ? &state->base : NULL((void *)0);
227}
228
229static void
230drm_bridge_atomic_destroy_priv_state(struct drm_private_obj *obj,
231 struct drm_private_state *s)
232{
233 struct drm_bridge_state *state = drm_priv_to_bridge_state(s);
234 struct drm_bridge *bridge = drm_priv_to_bridge(obj);
235
236 bridge->funcs->atomic_destroy_state(bridge, state);
237}
238
239static const struct drm_private_state_funcs drm_bridge_priv_state_funcs = {
240 .atomic_duplicate_state = drm_bridge_atomic_duplicate_priv_state,
241 .atomic_destroy_state = drm_bridge_atomic_destroy_priv_state,
242};
243
244/**
245 * drm_bridge_attach - attach the bridge to an encoder's chain
246 *
247 * @encoder: DRM encoder
248 * @bridge: bridge to attach
249 * @previous: previous bridge in the chain (optional)
250 * @flags: DRM_BRIDGE_ATTACH_* flags
251 *
252 * Called by a kms driver to link the bridge to an encoder's chain. The previous
253 * argument specifies the previous bridge in the chain. If NULL, the bridge is
254 * linked directly at the encoder's output. Otherwise it is linked at the
255 * previous bridge's output.
256 *
257 * If non-NULL the previous bridge must be already attached by a call to this
258 * function.
259 *
260 * Note that bridges attached to encoders are auto-detached during encoder
261 * cleanup in drm_encoder_cleanup(), so drm_bridge_attach() should generally
262 * *not* be balanced with a drm_bridge_detach() in driver code.
263 *
264 * RETURNS:
265 * Zero on success, error code on failure
266 */
267int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
268 struct drm_bridge *previous,
269 enum drm_bridge_attach_flags flags)
270{
271 int ret;
272
273 if (!encoder || !bridge)
274 return -EINVAL22;
275
276 if (previous && (!previous->dev || previous->encoder != encoder))
277 return -EINVAL22;
278
279 if (bridge->dev)
280 return -EBUSY16;
281
282 bridge->dev = encoder->dev;
283 bridge->encoder = encoder;
284
285 if (previous)
286 list_add(&bridge->chain_node, &previous->chain_node);
287 else
288 list_add(&bridge->chain_node, &encoder->bridge_chain);
289
290 if (bridge->funcs->attach) {
291 ret = bridge->funcs->attach(bridge, flags);
292 if (ret < 0)
293 goto err_reset_bridge;
294 }
295
296 if (bridge->funcs->atomic_reset) {
297 struct drm_bridge_state *state;
298
299 state = bridge->funcs->atomic_reset(bridge);
300 if (IS_ERR(state)) {
301 ret = PTR_ERR(state);
302 goto err_detach_bridge;
303 }
304
305 drm_atomic_private_obj_init(bridge->dev, &bridge->base,
306 &state->base,
307 &drm_bridge_priv_state_funcs);
308 }
309
310 return 0;
311
312err_detach_bridge:
313 if (bridge->funcs->detach)
314 bridge->funcs->detach(bridge);
315
316err_reset_bridge:
317 bridge->dev = NULL((void *)0);
318 bridge->encoder = NULL((void *)0);
319 list_del(&bridge->chain_node);
320
321#ifdef CONFIG_OF
322 DRM_ERROR("failed to attach bridge %pOF to encoder %s: %d\n",__drm_err("failed to attach bridge %pOF to encoder %s: %d\n",
bridge->of_node, encoder->name, ret)
323 bridge->of_node, encoder->name, ret)__drm_err("failed to attach bridge %pOF to encoder %s: %d\n",
bridge->of_node, encoder->name, ret);
324#else
325 DRM_ERROR("failed to attach bridge to encoder %s: %d\n",__drm_err("failed to attach bridge to encoder %s: %d\n", encoder
->name, ret)
326 encoder->name, ret)__drm_err("failed to attach bridge to encoder %s: %d\n", encoder
->name, ret);
327#endif
328
329 return ret;
330}
331EXPORT_SYMBOL(drm_bridge_attach);
332
333void drm_bridge_detach(struct drm_bridge *bridge)
334{
335 if (WARN_ON(!bridge)({ int __ret = !!(!bridge); if (__ret) printf("WARNING %s failed at %s:%d\n"
, "!bridge", "/usr/src/sys/dev/pci/drm/drm_bridge.c", 335); __builtin_expect
(!!(__ret), 0); }))
336 return;
337
338 if (WARN_ON(!bridge->dev)({ int __ret = !!(!bridge->dev); if (__ret) printf("WARNING %s failed at %s:%d\n"
, "!bridge->dev", "/usr/src/sys/dev/pci/drm/drm_bridge.c",
338); __builtin_expect(!!(__ret), 0); }))
339 return;
340
341 if (bridge->funcs->atomic_reset)
342 drm_atomic_private_obj_fini(&bridge->base);
343
344 if (bridge->funcs->detach)
345 bridge->funcs->detach(bridge);
346
347 list_del(&bridge->chain_node);
348 bridge->dev = NULL((void *)0);
349}
350
351/**
352 * DOC: bridge operations
353 *
354 * Bridge drivers expose operations through the &drm_bridge_funcs structure.
355 * The DRM internals (atomic and CRTC helpers) use the helpers defined in
356 * drm_bridge.c to call bridge operations. Those operations are divided in
357 * three big categories to support different parts of the bridge usage.
358 *
359 * - The encoder-related operations support control of the bridges in the
360 * chain, and are roughly counterparts to the &drm_encoder_helper_funcs
361 * operations. They are used by the legacy CRTC and the atomic modeset
362 * helpers to perform mode validation, fixup and setting, and enable and
363 * disable the bridge automatically.
364 *
365 * The enable and disable operations are split in
366 * &drm_bridge_funcs.pre_enable, &drm_bridge_funcs.enable,
367 * &drm_bridge_funcs.disable and &drm_bridge_funcs.post_disable to provide
368 * finer-grained control.
369 *
370 * Bridge drivers may implement the legacy version of those operations, or
371 * the atomic version (prefixed with atomic\_), in which case they shall also
372 * implement the atomic state bookkeeping operations
373 * (&drm_bridge_funcs.atomic_duplicate_state,
374 * &drm_bridge_funcs.atomic_destroy_state and &drm_bridge_funcs.reset).
375 * Mixing atomic and non-atomic versions of the operations is not supported.
376 *
377 * - The bus format negotiation operations
378 * &drm_bridge_funcs.atomic_get_output_bus_fmts and
379 * &drm_bridge_funcs.atomic_get_input_bus_fmts allow bridge drivers to
380 * negotiate the formats transmitted between bridges in the chain when
381 * multiple formats are supported. Negotiation for formats is performed
382 * transparently for display drivers by the atomic modeset helpers. Only
383 * atomic versions of those operations exist, bridge drivers that need to
384 * implement them shall thus also implement the atomic version of the
385 * encoder-related operations. This feature is not supported by the legacy
386 * CRTC helpers.
387 *
388 * - The connector-related operations support implementing a &drm_connector
389 * based on a chain of bridges. DRM bridges traditionally create a
390 * &drm_connector for bridges meant to be used at the end of the chain. This
391 * puts additional burden on bridge drivers, especially for bridges that may
392 * be used in the middle of a chain or at the end of it. Furthermore, it
393 * requires all operations of the &drm_connector to be handled by a single
394 * bridge, which doesn't always match the hardware architecture.
395 *
396 * To simplify bridge drivers and make the connector implementation more
397 * flexible, a new model allows bridges to unconditionally skip creation of
398 * &drm_connector and instead expose &drm_bridge_funcs operations to support
399 * an externally-implemented &drm_connector. Those operations are
400 * &drm_bridge_funcs.detect, &drm_bridge_funcs.get_modes,
401 * &drm_bridge_funcs.get_edid, &drm_bridge_funcs.hpd_notify,
402 * &drm_bridge_funcs.hpd_enable and &drm_bridge_funcs.hpd_disable. When
403 * implemented, display drivers shall create a &drm_connector instance for
404 * each chain of bridges, and implement those connector instances based on
405 * the bridge connector operations.
406 *
407 * Bridge drivers shall implement the connector-related operations for all
408 * the features that the bridge hardware support. For instance, if a bridge
409 * supports reading EDID, the &drm_bridge_funcs.get_edid shall be
410 * implemented. This however doesn't mean that the DDC lines are wired to the
411 * bridge on a particular platform, as they could also be connected to an I2C
412 * controller of the SoC. Support for the connector-related operations on the
413 * running platform is reported through the &drm_bridge.ops flags. Bridge
414 * drivers shall detect which operations they can support on the platform
415 * (usually this information is provided by ACPI or DT), and set the
416 * &drm_bridge.ops flags for all supported operations. A flag shall only be
417 * set if the corresponding &drm_bridge_funcs operation is implemented, but
418 * an implemented operation doesn't necessarily imply that the corresponding
419 * flag will be set. Display drivers shall use the &drm_bridge.ops flags to
420 * decide which bridge to delegate a connector operation to. This mechanism
421 * allows providing a single static const &drm_bridge_funcs instance in
422 * bridge drivers, improving security by storing function pointers in
423 * read-only memory.
424 *
425 * In order to ease transition, bridge drivers may support both the old and
426 * new models by making connector creation optional and implementing the
427 * connected-related bridge operations. Connector creation is then controlled
428 * by the flags argument to the drm_bridge_attach() function. Display drivers
429 * that support the new model and create connectors themselves shall set the
430 * %DRM_BRIDGE_ATTACH_NO_CONNECTOR flag, and bridge drivers shall then skip
431 * connector creation. For intermediate bridges in the chain, the flag shall
432 * be passed to the drm_bridge_attach() call for the downstream bridge.
433 * Bridge drivers that implement the new model only shall return an error
434 * from their &drm_bridge_funcs.attach handler when the
435 * %DRM_BRIDGE_ATTACH_NO_CONNECTOR flag is not set. New display drivers
436 * should use the new model, and convert the bridge drivers they use if
437 * needed, in order to gradually transition to the new model.
438 */
439
440/**
441 * drm_bridge_chain_mode_fixup - fixup proposed mode for all bridges in the
442 * encoder chain
443 * @bridge: bridge control structure
444 * @mode: desired mode to be set for the bridge
445 * @adjusted_mode: updated mode that works for this bridge
446 *
447 * Calls &drm_bridge_funcs.mode_fixup for all the bridges in the
448 * encoder chain, starting from the first bridge to the last.
449 *
450 * Note: the bridge passed should be the one closest to the encoder
451 *
452 * RETURNS:
453 * true on success, false on failure
454 */
455bool_Bool drm_bridge_chain_mode_fixup(struct drm_bridge *bridge,
456 const struct drm_display_mode *mode,
457 struct drm_display_mode *adjusted_mode)
458{
459 struct drm_encoder *encoder;
460
461 if (!bridge)
462 return true1;
463
464 encoder = bridge->encoder;
465 list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node)for (; &bridge->chain_node != (&encoder->bridge_chain
); bridge = ({ const __typeof( ((__typeof(*bridge) *)0)->chain_node
) *__mptr = (bridge->chain_node.next); (__typeof(*bridge)
*)( (char *)__mptr - __builtin_offsetof(__typeof(*bridge), chain_node
) );})) {
466 if (!bridge->funcs->mode_fixup)
467 continue;
468
469 if (!bridge->funcs->mode_fixup(bridge, mode, adjusted_mode))
470 return false0;
471 }
472
473 return true1;
474}
475EXPORT_SYMBOL(drm_bridge_chain_mode_fixup);
476
477/**
478 * drm_bridge_chain_mode_valid - validate the mode against all bridges in the
479 * encoder chain.
480 * @bridge: bridge control structure
481 * @info: display info against which the mode shall be validated
482 * @mode: desired mode to be validated
483 *
484 * Calls &drm_bridge_funcs.mode_valid for all the bridges in the encoder
485 * chain, starting from the first bridge to the last. If at least one bridge
486 * does not accept the mode the function returns the error code.
487 *
488 * Note: the bridge passed should be the one closest to the encoder.
489 *
490 * RETURNS:
491 * MODE_OK on success, drm_mode_status Enum error code on failure
492 */
493enum drm_mode_status
494drm_bridge_chain_mode_valid(struct drm_bridge *bridge,
495 const struct drm_display_info *info,
496 const struct drm_display_mode *mode)
497{
498 struct drm_encoder *encoder;
499
500 if (!bridge)
501 return MODE_OK;
502
503 encoder = bridge->encoder;
504 list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node)for (; &bridge->chain_node != (&encoder->bridge_chain
); bridge = ({ const __typeof( ((__typeof(*bridge) *)0)->chain_node
) *__mptr = (bridge->chain_node.next); (__typeof(*bridge)
*)( (char *)__mptr - __builtin_offsetof(__typeof(*bridge), chain_node
) );})) {
505 enum drm_mode_status ret;
506
507 if (!bridge->funcs->mode_valid)
508 continue;
509
510 ret = bridge->funcs->mode_valid(bridge, info, mode);
511 if (ret != MODE_OK)
512 return ret;
513 }
514
515 return MODE_OK;
516}
517EXPORT_SYMBOL(drm_bridge_chain_mode_valid);
518
519/**
520 * drm_bridge_chain_disable - disables all bridges in the encoder chain
521 * @bridge: bridge control structure
522 *
523 * Calls &drm_bridge_funcs.disable op for all the bridges in the encoder
524 * chain, starting from the last bridge to the first. These are called before
525 * calling the encoder's prepare op.
526 *
527 * Note: the bridge passed should be the one closest to the encoder
528 */
529void drm_bridge_chain_disable(struct drm_bridge *bridge)
530{
531 struct drm_encoder *encoder;
532 struct drm_bridge *iter;
533
534 if (!bridge)
535 return;
536
537 encoder = bridge->encoder;
538 list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node)for (iter = ({ const __typeof( ((__typeof(*iter) *)0)->chain_node
) *__mptr = ((&encoder->bridge_chain)->prev); (__typeof
(*iter) *)( (char *)__mptr - __builtin_offsetof(__typeof(*iter
), chain_node) );}); &iter->chain_node != (&encoder
->bridge_chain); iter = ({ const __typeof( ((__typeof(*iter
) *)0)->chain_node ) *__mptr = (iter->chain_node.prev);
(__typeof(*iter) *)( (char *)__mptr - __builtin_offsetof(__typeof
(*iter), chain_node) );})) {
539 if (iter->funcs->disable)
540 iter->funcs->disable(iter);
541
542 if (iter == bridge)
543 break;
544 }
545}
546EXPORT_SYMBOL(drm_bridge_chain_disable);
547
548/**
549 * drm_bridge_chain_post_disable - cleans up after disabling all bridges in the
550 * encoder chain
551 * @bridge: bridge control structure
552 *
553 * Calls &drm_bridge_funcs.post_disable op for all the bridges in the
554 * encoder chain, starting from the first bridge to the last. These are called
555 * after completing the encoder's prepare op.
556 *
557 * Note: the bridge passed should be the one closest to the encoder
558 */
559void drm_bridge_chain_post_disable(struct drm_bridge *bridge)
560{
561 struct drm_encoder *encoder;
562
563 if (!bridge)
564 return;
565
566 encoder = bridge->encoder;
567 list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node)for (; &bridge->chain_node != (&encoder->bridge_chain
); bridge = ({ const __typeof( ((__typeof(*bridge) *)0)->chain_node
) *__mptr = (bridge->chain_node.next); (__typeof(*bridge)
*)( (char *)__mptr - __builtin_offsetof(__typeof(*bridge), chain_node
) );})) {
568 if (bridge->funcs->post_disable)
569 bridge->funcs->post_disable(bridge);
570 }
571}
572EXPORT_SYMBOL(drm_bridge_chain_post_disable);
573
574/**
575 * drm_bridge_chain_mode_set - set proposed mode for all bridges in the
576 * encoder chain
577 * @bridge: bridge control structure
578 * @mode: desired mode to be set for the encoder chain
579 * @adjusted_mode: updated mode that works for this encoder chain
580 *
581 * Calls &drm_bridge_funcs.mode_set op for all the bridges in the
582 * encoder chain, starting from the first bridge to the last.
583 *
584 * Note: the bridge passed should be the one closest to the encoder
585 */
586void drm_bridge_chain_mode_set(struct drm_bridge *bridge,
587 const struct drm_display_mode *mode,
588 const struct drm_display_mode *adjusted_mode)
589{
590 struct drm_encoder *encoder;
591
592 if (!bridge)
593 return;
594
595 encoder = bridge->encoder;
596 list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node)for (; &bridge->chain_node != (&encoder->bridge_chain
); bridge = ({ const __typeof( ((__typeof(*bridge) *)0)->chain_node
) *__mptr = (bridge->chain_node.next); (__typeof(*bridge)
*)( (char *)__mptr - __builtin_offsetof(__typeof(*bridge), chain_node
) );})) {
597 if (bridge->funcs->mode_set)
598 bridge->funcs->mode_set(bridge, mode, adjusted_mode);
599 }
600}
601EXPORT_SYMBOL(drm_bridge_chain_mode_set);
602
603/**
604 * drm_bridge_chain_pre_enable - prepares for enabling all bridges in the
605 * encoder chain
606 * @bridge: bridge control structure
607 *
608 * Calls &drm_bridge_funcs.pre_enable op for all the bridges in the encoder
609 * chain, starting from the last bridge to the first. These are called
610 * before calling the encoder's commit op.
611 *
612 * Note: the bridge passed should be the one closest to the encoder
613 */
614void drm_bridge_chain_pre_enable(struct drm_bridge *bridge)
615{
616 struct drm_encoder *encoder;
617 struct drm_bridge *iter;
618
619 if (!bridge)
620 return;
621
622 encoder = bridge->encoder;
623 list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node)for (iter = ({ const __typeof( ((__typeof(*iter) *)0)->chain_node
) *__mptr = ((&encoder->bridge_chain)->prev); (__typeof
(*iter) *)( (char *)__mptr - __builtin_offsetof(__typeof(*iter
), chain_node) );}); &iter->chain_node != (&encoder
->bridge_chain); iter = ({ const __typeof( ((__typeof(*iter
) *)0)->chain_node ) *__mptr = (iter->chain_node.prev);
(__typeof(*iter) *)( (char *)__mptr - __builtin_offsetof(__typeof
(*iter), chain_node) );})) {
624 if (iter->funcs->pre_enable)
625 iter->funcs->pre_enable(iter);
626
627 if (iter == bridge)
628 break;
629 }
630}
631EXPORT_SYMBOL(drm_bridge_chain_pre_enable);
632
633/**
634 * drm_bridge_chain_enable - enables all bridges in the encoder chain
635 * @bridge: bridge control structure
636 *
637 * Calls &drm_bridge_funcs.enable op for all the bridges in the encoder
638 * chain, starting from the first bridge to the last. These are called
639 * after completing the encoder's commit op.
640 *
641 * Note that the bridge passed should be the one closest to the encoder
642 */
643void drm_bridge_chain_enable(struct drm_bridge *bridge)
644{
645 struct drm_encoder *encoder;
646
647 if (!bridge)
648 return;
649
650 encoder = bridge->encoder;
651 list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node)for (; &bridge->chain_node != (&encoder->bridge_chain
); bridge = ({ const __typeof( ((__typeof(*bridge) *)0)->chain_node
) *__mptr = (bridge->chain_node.next); (__typeof(*bridge)
*)( (char *)__mptr - __builtin_offsetof(__typeof(*bridge), chain_node
) );})) {
652 if (bridge->funcs->enable)
653 bridge->funcs->enable(bridge);
654 }
655}
656EXPORT_SYMBOL(drm_bridge_chain_enable);
657
658/**
659 * drm_atomic_bridge_chain_disable - disables all bridges in the encoder chain
660 * @bridge: bridge control structure
661 * @old_state: old atomic state
662 *
663 * Calls &drm_bridge_funcs.atomic_disable (falls back on
664 * &drm_bridge_funcs.disable) op for all the bridges in the encoder chain,
665 * starting from the last bridge to the first. These are called before calling
666 * &drm_encoder_helper_funcs.atomic_disable
667 *
668 * Note: the bridge passed should be the one closest to the encoder
669 */
670void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,
671 struct drm_atomic_state *old_state)
672{
673 struct drm_encoder *encoder;
674 struct drm_bridge *iter;
675
676 if (!bridge)
677 return;
678
679 encoder = bridge->encoder;
680 list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node)for (iter = ({ const __typeof( ((__typeof(*iter) *)0)->chain_node
) *__mptr = ((&encoder->bridge_chain)->prev); (__typeof
(*iter) *)( (char *)__mptr - __builtin_offsetof(__typeof(*iter
), chain_node) );}); &iter->chain_node != (&encoder
->bridge_chain); iter = ({ const __typeof( ((__typeof(*iter
) *)0)->chain_node ) *__mptr = (iter->chain_node.prev);
(__typeof(*iter) *)( (char *)__mptr - __builtin_offsetof(__typeof
(*iter), chain_node) );})) {
681 if (iter->funcs->atomic_disable) {
682 struct drm_bridge_state *old_bridge_state;
683
684 old_bridge_state =
685 drm_atomic_get_old_bridge_state(old_state,
686 iter);
687 if (WARN_ON(!old_bridge_state)({ int __ret = !!(!old_bridge_state); if (__ret) printf("WARNING %s failed at %s:%d\n"
, "!old_bridge_state", "/usr/src/sys/dev/pci/drm/drm_bridge.c"
, 687); __builtin_expect(!!(__ret), 0); }))
688 return;
689
690 iter->funcs->atomic_disable(iter, old_bridge_state);
691 } else if (iter->funcs->disable) {
692 iter->funcs->disable(iter);
693 }
694
695 if (iter == bridge)
696 break;
697 }
698}
699EXPORT_SYMBOL(drm_atomic_bridge_chain_disable);
700
701static void drm_atomic_bridge_call_post_disable(struct drm_bridge *bridge,
702 struct drm_atomic_state *old_state)
703{
704 if (old_state && bridge->funcs->atomic_post_disable) {
705 struct drm_bridge_state *old_bridge_state;
706
707 old_bridge_state =
708 drm_atomic_get_old_bridge_state(old_state,
709 bridge);
710 if (WARN_ON(!old_bridge_state)({ int __ret = !!(!old_bridge_state); if (__ret) printf("WARNING %s failed at %s:%d\n"
, "!old_bridge_state", "/usr/src/sys/dev/pci/drm/drm_bridge.c"
, 710); __builtin_expect(!!(__ret), 0); }))
711 return;
712
713 bridge->funcs->atomic_post_disable(bridge,
714 old_bridge_state);
715 } else if (bridge->funcs->post_disable) {
716 bridge->funcs->post_disable(bridge);
717 }
718}
719
720/**
721 * drm_atomic_bridge_chain_post_disable - cleans up after disabling all bridges
722 * in the encoder chain
723 * @bridge: bridge control structure
724 * @old_state: old atomic state
725 *
726 * Calls &drm_bridge_funcs.atomic_post_disable (falls back on
727 * &drm_bridge_funcs.post_disable) op for all the bridges in the encoder chain,
728 * starting from the first bridge to the last. These are called after completing
729 * &drm_encoder_helper_funcs.atomic_disable
730 *
731 * If a bridge sets @pre_enable_prev_first, then the @post_disable for that
732 * bridge will be called before the previous one to reverse the @pre_enable
733 * calling direction.
734 *
735 * Note: the bridge passed should be the one closest to the encoder
736 */
737void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
738 struct drm_atomic_state *old_state)
739{
740 struct drm_encoder *encoder;
741 struct drm_bridge *next, *limit;
742
743 if (!bridge)
744 return;
745
746 encoder = bridge->encoder;
747
748 list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node)for (; &bridge->chain_node != (&encoder->bridge_chain
); bridge = ({ const __typeof( ((__typeof(*bridge) *)0)->chain_node
) *__mptr = (bridge->chain_node.next); (__typeof(*bridge)
*)( (char *)__mptr - __builtin_offsetof(__typeof(*bridge), chain_node
) );})) {
749 limit = NULL((void *)0);
750
751 if (!list_is_last(&bridge->chain_node, &encoder->bridge_chain)) {
752 next = list_next_entry(bridge, chain_node)({ const __typeof( ((typeof(*(bridge)) *)0)->chain_node ) *
__mptr = (((bridge)->chain_node.next)); (typeof(*(bridge))
*)( (char *)__mptr - __builtin_offsetof(typeof(*(bridge)), chain_node
) );});
753
754 if (next->pre_enable_prev_first) {
755 /* next bridge had requested that prev
756 * was enabled first, so disabled last
757 */
758 limit = next;
759
760 /* Find the next bridge that has NOT requested
761 * prev to be enabled first / disabled last
762 */
763 list_for_each_entry_from(next, &encoder->bridge_chain,for (; &next->chain_node != (&encoder->bridge_chain
); next = ({ const __typeof( ((__typeof(*next) *)0)->chain_node
) *__mptr = (next->chain_node.next); (__typeof(*next) *)(
(char *)__mptr - __builtin_offsetof(__typeof(*next), chain_node
) );}))
764 chain_node)for (; &next->chain_node != (&encoder->bridge_chain
); next = ({ const __typeof( ((__typeof(*next) *)0)->chain_node
) *__mptr = (next->chain_node.next); (__typeof(*next) *)(
(char *)__mptr - __builtin_offsetof(__typeof(*next), chain_node
) );})) {
765 if (next->pre_enable_prev_first) {
766 next = list_prev_entry(next, chain_node)({ const __typeof( ((typeof(*(next)) *)0)->chain_node ) *__mptr
= (((next)->chain_node.prev)); (typeof(*(next)) *)( (char
*)__mptr - __builtin_offsetof(typeof(*(next)), chain_node) )
;});
767 limit = next;
768 break;
769 }
770 }
771
772 /* Call these bridges in reverse order */
773 list_for_each_entry_from_reverse(next, &encoder->bridge_chain,for (; &next->chain_node != (&encoder->bridge_chain
); next = ({ const __typeof( ((__typeof(*next) *)0)->chain_node
) *__mptr = (next->chain_node.prev); (__typeof(*next) *)(
(char *)__mptr - __builtin_offsetof(__typeof(*next), chain_node
) );}))
774 chain_node)for (; &next->chain_node != (&encoder->bridge_chain
); next = ({ const __typeof( ((__typeof(*next) *)0)->chain_node
) *__mptr = (next->chain_node.prev); (__typeof(*next) *)(
(char *)__mptr - __builtin_offsetof(__typeof(*next), chain_node
) );})) {
775 if (next == bridge)
776 break;
777
778 drm_atomic_bridge_call_post_disable(next,
779 old_state);
780 }
781 }
782 }
783
784 drm_atomic_bridge_call_post_disable(bridge, old_state);
785
786 if (limit)
787 /* Jump all bridges that we have already post_disabled */
788 bridge = limit;
789 }
790}
791EXPORT_SYMBOL(drm_atomic_bridge_chain_post_disable);
792
793static void drm_atomic_bridge_call_pre_enable(struct drm_bridge *bridge,
794 struct drm_atomic_state *old_state)
795{
796 if (old_state && bridge->funcs->atomic_pre_enable) {
8
←
Assuming 'old_state' is null
→
797 struct drm_bridge_state *old_bridge_state;
798
799 old_bridge_state =
800 drm_atomic_get_old_bridge_state(old_state,
801 bridge);
802 if (WARN_ON(!old_bridge_state)({ int __ret = !!(!old_bridge_state); if (__ret) printf("WARNING %s failed at %s:%d\n"
, "!old_bridge_state", "/usr/src/sys/dev/pci/drm/drm_bridge.c"
, 802); __builtin_expect(!!(__ret), 0); }))
803 return;
804
805 bridge->funcs->atomic_pre_enable(bridge, old_bridge_state);
806 } else if (bridge->funcs->pre_enable) {
9
←
Assuming field 'pre_enable' is non-null
→
10
←
Taking true branch
→
807 bridge->funcs->pre_enable(bridge);
11
←
Value assigned to field 'pre_enable_prev_first', which participates in a condition later
→
808 }
809}
810
811/**
812 * drm_atomic_bridge_chain_pre_enable - prepares for enabling all bridges in
813 * the encoder chain
814 * @bridge: bridge control structure
815 * @old_state: old atomic state
816 *
817 * Calls &drm_bridge_funcs.atomic_pre_enable (falls back on
818 * &drm_bridge_funcs.pre_enable) op for all the bridges in the encoder chain,
819 * starting from the last bridge to the first. These are called before calling
820 * &drm_encoder_helper_funcs.atomic_enable
821 *
822 * If a bridge sets @pre_enable_prev_first, then the pre_enable for the
823 * prev bridge will be called before pre_enable of this bridge.
824 *
825 * Note: the bridge passed should be the one closest to the encoder
826 */
827void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
828 struct drm_atomic_state *old_state)
829{
830 struct drm_encoder *encoder;
831 struct drm_bridge *iter, *next, *limit;
1
'limit' declared without an initial value
→
832
833 if (!bridge)
2
←
Assuming 'bridge' is non-null
→
3
←
Taking false branch
→
834 return;
835
836 encoder = bridge->encoder;
837
838 list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node)for (iter = ({ const __typeof( ((__typeof(*iter) *)0)->chain_node
) *__mptr = ((&encoder->bridge_chain)->prev); (__typeof
(*iter) *)( (char *)__mptr - __builtin_offsetof(__typeof(*iter
), chain_node) );}); &iter->chain_node != (&encoder
->bridge_chain); iter = ({ const __typeof( ((__typeof(*iter
) *)0)->chain_node ) *__mptr = (iter->chain_node.prev);
(__typeof(*iter) *)( (char *)__mptr - __builtin_offsetof(__typeof
(*iter), chain_node) );})) {
4
←
Loop condition is true. Entering loop body
→
839 if (iter->pre_enable_prev_first) {
5
←
Assuming field 'pre_enable_prev_first' is false
→
6
←
Taking false branch
→
840 next = iter;
841 limit = bridge;
842 list_for_each_entry_from_reverse(next,for (; &next->chain_node != (&encoder->bridge_chain
); next = ({ const __typeof( ((__typeof(*next) *)0)->chain_node
) *__mptr = (next->chain_node.prev); (__typeof(*next) *)(
(char *)__mptr - __builtin_offsetof(__typeof(*next), chain_node
) );}))
843 &encoder->bridge_chain,for (; &next->chain_node != (&encoder->bridge_chain
); next = ({ const __typeof( ((__typeof(*next) *)0)->chain_node
) *__mptr = (next->chain_node.prev); (__typeof(*next) *)(
(char *)__mptr - __builtin_offsetof(__typeof(*next), chain_node
) );}))
844 chain_node)for (; &next->chain_node != (&encoder->bridge_chain
); next = ({ const __typeof( ((__typeof(*next) *)0)->chain_node
) *__mptr = (next->chain_node.prev); (__typeof(*next) *)(
(char *)__mptr - __builtin_offsetof(__typeof(*next), chain_node
) );})) {
845 if (next == bridge)
846 break;
847
848 if (!next->pre_enable_prev_first) {
849 /* Found first bridge that does NOT
850 * request prev to be enabled first
851 */
852 limit = list_prev_entry(next, chain_node)({ const __typeof( ((typeof(*(next)) *)0)->chain_node ) *__mptr
= (((next)->chain_node.prev)); (typeof(*(next)) *)( (char
*)__mptr - __builtin_offsetof(typeof(*(next)), chain_node) )
;});
853 break;
854 }
855 }
856
857 list_for_each_entry_from(next, &encoder->bridge_chain, chain_node)for (; &next->chain_node != (&encoder->bridge_chain
); next = ({ const __typeof( ((__typeof(*next) *)0)->chain_node
) *__mptr = (next->chain_node.next); (__typeof(*next) *)(
(char *)__mptr - __builtin_offsetof(__typeof(*next), chain_node
) );})) {
858 /* Call requested prev bridge pre_enable
859 * in order.
860 */
861 if (next == iter)
862 /* At the first bridge to request prev
863 * bridges called first.
864 */
865 break;
866
867 drm_atomic_bridge_call_pre_enable(next, old_state);
868 }
869 }
870
871 drm_atomic_bridge_call_pre_enable(iter, old_state);
7
←
Calling 'drm_atomic_bridge_call_pre_enable'
→
12
←
Returning from 'drm_atomic_bridge_call_pre_enable'
→
872
873 if (iter->pre_enable_prev_first)
13
←
Assuming field 'pre_enable_prev_first' is true
→
14
←
Taking true branch
→
874 /* Jump all bridges that we have already pre_enabled */
875 iter = limit;
15
←
Assigned value is garbage or undefined
876
877 if (iter == bridge)
878 break;
879 }
880}
881EXPORT_SYMBOL(drm_atomic_bridge_chain_pre_enable);
882
883/**
884 * drm_atomic_bridge_chain_enable - enables all bridges in the encoder chain
885 * @bridge: bridge control structure
886 * @old_state: old atomic state
887 *
888 * Calls &drm_bridge_funcs.atomic_enable (falls back on
889 * &drm_bridge_funcs.enable) op for all the bridges in the encoder chain,
890 * starting from the first bridge to the last. These are called after completing
891 * &drm_encoder_helper_funcs.atomic_enable
892 *
893 * Note: the bridge passed should be the one closest to the encoder
894 */
895void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
896 struct drm_atomic_state *old_state)
897{
898 struct drm_encoder *encoder;
899
900 if (!bridge)
901 return;
902
903 encoder = bridge->encoder;
904 list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node)for (; &bridge->chain_node != (&encoder->bridge_chain
); bridge = ({ const __typeof( ((__typeof(*bridge) *)0)->chain_node
) *__mptr = (bridge->chain_node.next); (__typeof(*bridge)
*)( (char *)__mptr - __builtin_offsetof(__typeof(*bridge), chain_node
) );})) {
905 if (bridge->funcs->atomic_enable) {
906 struct drm_bridge_state *old_bridge_state;
907
908 old_bridge_state =
909 drm_atomic_get_old_bridge_state(old_state,
910 bridge);
911 if (WARN_ON(!old_bridge_state)({ int __ret = !!(!old_bridge_state); if (__ret) printf("WARNING %s failed at %s:%d\n"
, "!old_bridge_state", "/usr/src/sys/dev/pci/drm/drm_bridge.c"
, 911); __builtin_expect(!!(__ret), 0); }))
912 return;
913
914 bridge->funcs->atomic_enable(bridge, old_bridge_state);
915 } else if (bridge->funcs->enable) {
916 bridge->funcs->enable(bridge);
917 }
918 }
919}
920EXPORT_SYMBOL(drm_atomic_bridge_chain_enable);
921
922static int drm_atomic_bridge_check(struct drm_bridge *bridge,
923 struct drm_crtc_state *crtc_state,
924 struct drm_connector_state *conn_state)
925{
926 if (bridge->funcs->atomic_check) {
927 struct drm_bridge_state *bridge_state;
928 int ret;
929
930 bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
931 bridge);
932 if (WARN_ON(!bridge_state)({ int __ret = !!(!bridge_state); if (__ret) printf("WARNING %s failed at %s:%d\n"
, "!bridge_state", "/usr/src/sys/dev/pci/drm/drm_bridge.c", 932
); __builtin_expect(!!(__ret), 0); }))
933 return -EINVAL22;
934
935 ret = bridge->funcs->atomic_check(bridge, bridge_state,
936 crtc_state, conn_state);
937 if (ret)
938 return ret;
939 } else if (bridge->funcs->mode_fixup) {
940 if (!bridge->funcs->mode_fixup(bridge, &crtc_state->mode,
941 &crtc_state->adjusted_mode))
942 return -EINVAL22;
943 }
944
945 return 0;
946}
947
948static int select_bus_fmt_recursive(struct drm_bridge *first_bridge,
949 struct drm_bridge *cur_bridge,
950 struct drm_crtc_state *crtc_state,
951 struct drm_connector_state *conn_state,
952 u32 out_bus_fmt)
953{
954 unsigned int i, num_in_bus_fmts = 0;
955 struct drm_bridge_state *cur_state;
956 struct drm_bridge *prev_bridge;
957 u32 *in_bus_fmts;
958 int ret;
959
960 prev_bridge = drm_bridge_get_prev_bridge(cur_bridge);
961 cur_state = drm_atomic_get_new_bridge_state(crtc_state->state,
962 cur_bridge);
963
964 /*
965 * If bus format negotiation is not supported by this bridge, let's
966 * pass MEDIA_BUS_FMT_FIXED to the previous bridge in the chain and
967 * hope that it can handle this situation gracefully (by providing
968 * appropriate default values).
969 */
970 if (!cur_bridge->funcs->atomic_get_input_bus_fmts) {
971 if (cur_bridge != first_bridge) {
972 ret = select_bus_fmt_recursive(first_bridge,
973 prev_bridge, crtc_state,
974 conn_state,
975 MEDIA_BUS_FMT_FIXED1);
976 if (ret)
977 return ret;
978 }
979
980 /*
981 * Driver does not implement the atomic state hooks, but that's
982 * fine, as long as it does not access the bridge state.
983 */
984 if (cur_state) {
985 cur_state->input_bus_cfg.format = MEDIA_BUS_FMT_FIXED1;
986 cur_state->output_bus_cfg.format = out_bus_fmt;
987 }
988
989 return 0;
990 }
991
992 /*
993 * If the driver implements ->atomic_get_input_bus_fmts() it
994 * should also implement the atomic state hooks.
995 */
996 if (WARN_ON(!cur_state)({ int __ret = !!(!cur_state); if (__ret) printf("WARNING %s failed at %s:%d\n"
, "!cur_state", "/usr/src/sys/dev/pci/drm/drm_bridge.c", 996)
; __builtin_expect(!!(__ret), 0); }))
997 return -EINVAL22;
998
999 in_bus_fmts = cur_bridge->funcs->atomic_get_input_bus_fmts(cur_bridge,
1000 cur_state,
1001 crtc_state,
1002 conn_state,
1003 out_bus_fmt,
1004 &num_in_bus_fmts);
1005 if (!num_in_bus_fmts)
1006 return -ENOTSUPP91;
1007 else if (!in_bus_fmts)
1008 return -ENOMEM12;
1009
1010 if (first_bridge == cur_bridge) {
1011 cur_state->input_bus_cfg.format = in_bus_fmts[0];
1012 cur_state->output_bus_cfg.format = out_bus_fmt;
1013 kfree(in_bus_fmts);
1014 return 0;
1015 }
1016
1017 for (i = 0; i < num_in_bus_fmts; i++) {
1018 ret = select_bus_fmt_recursive(first_bridge, prev_bridge,
1019 crtc_state, conn_state,
1020 in_bus_fmts[i]);
1021 if (ret != -ENOTSUPP91)
1022 break;
1023 }
1024
1025 if (!ret) {
1026 cur_state->input_bus_cfg.format = in_bus_fmts[i];
1027 cur_state->output_bus_cfg.format = out_bus_fmt;
1028 }
1029
1030 kfree(in_bus_fmts);
1031 return ret;
1032}
1033
1034/*
1035 * This function is called by &drm_atomic_bridge_chain_check() just before
1036 * calling &drm_bridge_funcs.atomic_check() on all elements of the chain.
1037 * It performs bus format negotiation between bridge elements. The negotiation
1038 * happens in reverse order, starting from the last element in the chain up to
1039 * @bridge.
1040 *
1041 * Negotiation starts by retrieving supported output bus formats on the last
1042 * bridge element and testing them one by one. The test is recursive, meaning
1043 * that for each tested output format, the whole chain will be walked backward,
1044 * and each element will have to choose an input bus format that can be
1045 * transcoded to the requested output format. When a bridge element does not
1046 * support transcoding into a specific output format -ENOTSUPP is returned and
1047 * the next bridge element will have to try a different format. If none of the
1048 * combinations worked, -ENOTSUPP is returned and the atomic modeset will fail.
1049 *
1050 * This implementation is relying on
1051 * &drm_bridge_funcs.atomic_get_output_bus_fmts() and
1052 * &drm_bridge_funcs.atomic_get_input_bus_fmts() to gather supported
1053 * input/output formats.
1054 *
1055 * When &drm_bridge_funcs.atomic_get_output_bus_fmts() is not implemented by
1056 * the last element of the chain, &drm_atomic_bridge_chain_select_bus_fmts()
1057 * tries a single format: &drm_connector.display_info.bus_formats[0] if
1058 * available, MEDIA_BUS_FMT_FIXED otherwise.
1059 *
1060 * When &drm_bridge_funcs.atomic_get_input_bus_fmts() is not implemented,
1061 * &drm_atomic_bridge_chain_select_bus_fmts() skips the negotiation on the
1062 * bridge element that lacks this hook and asks the previous element in the
1063 * chain to try MEDIA_BUS_FMT_FIXED. It's up to bridge drivers to decide what
1064 * to do in that case (fail if they want to enforce bus format negotiation, or
1065 * provide a reasonable default if they need to support pipelines where not
1066 * all elements support bus format negotiation).
1067 */
1068static int
1069drm_atomic_bridge_chain_select_bus_fmts(struct drm_bridge *bridge,
1070 struct drm_crtc_state *crtc_state,
1071 struct drm_connector_state *conn_state)
1072{
1073 struct drm_connector *conn = conn_state->connector;
1074 struct drm_encoder *encoder = bridge->encoder;
1075 struct drm_bridge_state *last_bridge_state;
1076 unsigned int i, num_out_bus_fmts = 0;
1077 struct drm_bridge *last_bridge;
1078 u32 *out_bus_fmts;
1079 int ret = 0;
1080
1081 last_bridge = list_last_entry(&encoder->bridge_chain,({ const __typeof( ((struct drm_bridge *)0)->chain_node ) *
__mptr = ((&encoder->bridge_chain)->prev); (struct drm_bridge
*)( (char *)__mptr - __builtin_offsetof(struct drm_bridge, chain_node
) );})
1082 struct drm_bridge, chain_node)({ const __typeof( ((struct drm_bridge *)0)->chain_node ) *
__mptr = ((&encoder->bridge_chain)->prev); (struct drm_bridge
*)( (char *)__mptr - __builtin_offsetof(struct drm_bridge, chain_node
) );});
1083 last_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
1084 last_bridge);
1085
1086 if (last_bridge->funcs->atomic_get_output_bus_fmts) {
1087 const struct drm_bridge_funcs *funcs = last_bridge->funcs;
1088
1089 /*
1090 * If the driver implements ->atomic_get_output_bus_fmts() it
1091 * should also implement the atomic state hooks.
1092 */
1093 if (WARN_ON(!last_bridge_state)({ int __ret = !!(!last_bridge_state); if (__ret) printf("WARNING %s failed at %s:%d\n"
, "!last_bridge_state", "/usr/src/sys/dev/pci/drm/drm_bridge.c"
, 1093); __builtin_expect(!!(__ret), 0); }))
1094 return -EINVAL22;
1095
1096 out_bus_fmts = funcs->atomic_get_output_bus_fmts(last_bridge,
1097 last_bridge_state,
1098 crtc_state,
1099 conn_state,
1100 &num_out_bus_fmts);
1101 if (!num_out_bus_fmts)
1102 return -ENOTSUPP91;
1103 else if (!out_bus_fmts)
1104 return -ENOMEM12;
1105 } else {
1106 num_out_bus_fmts = 1;
1107 out_bus_fmts = kmalloc(sizeof(*out_bus_fmts), GFP_KERNEL(0x0001 | 0x0004));
1108 if (!out_bus_fmts)
1109 return -ENOMEM12;
1110
1111 if (conn->display_info.num_bus_formats &&
1112 conn->display_info.bus_formats)
1113 out_bus_fmts[0] = conn->display_info.bus_formats[0];
1114 else
1115 out_bus_fmts[0] = MEDIA_BUS_FMT_FIXED1;
1116 }
1117
1118 for (i = 0; i < num_out_bus_fmts; i++) {
1119 ret = select_bus_fmt_recursive(bridge, last_bridge, crtc_state,
1120 conn_state, out_bus_fmts[i]);
1121 if (ret != -ENOTSUPP91)
1122 break;
1123 }
1124
1125 kfree(out_bus_fmts);
1126
1127 return ret;
1128}
1129
1130static void
1131drm_atomic_bridge_propagate_bus_flags(struct drm_bridge *bridge,
1132 struct drm_connector *conn,
1133 struct drm_atomic_state *state)
1134{
1135 struct drm_bridge_state *bridge_state, *next_bridge_state;
1136 struct drm_bridge *next_bridge;
1137 u32 output_flags = 0;
1138
1139 bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
1140
1141 /* No bridge state attached to this bridge => nothing to propagate. */
1142 if (!bridge_state)
1143 return;
1144
1145 next_bridge = drm_bridge_get_next_bridge(bridge);
1146
1147 /*
1148 * Let's try to apply the most common case here, that is, propagate
1149 * display_info flags for the last bridge, and propagate the input
1150 * flags of the next bridge element to the output end of the current
1151 * bridge when the bridge is not the last one.
1152 * There are exceptions to this rule, like when signal inversion is
1153 * happening at the board level, but that's something drivers can deal
1154 * with from their &drm_bridge_funcs.atomic_check() implementation by
1155 * simply overriding the flags value we've set here.
1156 */
1157 if (!next_bridge) {
1158 output_flags = conn->display_info.bus_flags;
1159 } else {
1160 next_bridge_state = drm_atomic_get_new_bridge_state(state,
1161 next_bridge);
1162 /*
1163 * No bridge state attached to the next bridge, just leave the
1164 * flags to 0.
1165 */
1166 if (next_bridge_state)
1167 output_flags = next_bridge_state->input_bus_cfg.flags;
1168 }
1169
1170 bridge_state->output_bus_cfg.flags = output_flags;
1171
1172 /*
1173 * Propagate the output flags to the input end of the bridge. Again, it's
1174 * not necessarily what all bridges want, but that's what most of them
1175 * do, and by doing that by default we avoid forcing drivers to
1176 * duplicate the "dummy propagation" logic.
1177 */
1178 bridge_state->input_bus_cfg.flags = output_flags;
1179}
1180
1181/**
1182 * drm_atomic_bridge_chain_check() - Do an atomic check on the bridge chain
1183 * @bridge: bridge control structure
1184 * @crtc_state: new CRTC state
1185 * @conn_state: new connector state
1186 *
1187 * First trigger a bus format negotiation before calling
1188 * &drm_bridge_funcs.atomic_check() (falls back on
1189 * &drm_bridge_funcs.mode_fixup()) op for all the bridges in the encoder chain,
1190 * starting from the last bridge to the first. These are called before calling
1191 * &drm_encoder_helper_funcs.atomic_check()
1192 *
1193 * RETURNS:
1194 * 0 on success, a negative error code on failure
1195 */
1196int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
1197 struct drm_crtc_state *crtc_state,
1198 struct drm_connector_state *conn_state)
1199{
1200 struct drm_connector *conn = conn_state->connector;
1201 struct drm_encoder *encoder;
1202 struct drm_bridge *iter;
1203 int ret;
1204
1205 if (!bridge)
1206 return 0;
1207
1208 ret = drm_atomic_bridge_chain_select_bus_fmts(bridge, crtc_state,
1209 conn_state);
1210 if (ret)
1211 return ret;
1212
1213 encoder = bridge->encoder;
1214 list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node)for (iter = ({ const __typeof( ((__typeof(*iter) *)0)->chain_node
) *__mptr = ((&encoder->bridge_chain)->prev); (__typeof
(*iter) *)( (char *)__mptr - __builtin_offsetof(__typeof(*iter
), chain_node) );}); &iter->chain_node != (&encoder
->bridge_chain); iter = ({ const __typeof( ((__typeof(*iter
) *)0)->chain_node ) *__mptr = (iter->chain_node.prev);
(__typeof(*iter) *)( (char *)__mptr - __builtin_offsetof(__typeof
(*iter), chain_node) );})) {
1215 int ret;
1216
1217 /*
1218 * Bus flags are propagated by default. If a bridge needs to
1219 * tweak the input bus flags for any reason, it should happen
1220 * in its &drm_bridge_funcs.atomic_check() implementation such
1221 * that preceding bridges in the chain can propagate the new
1222 * bus flags.
1223 */
1224 drm_atomic_bridge_propagate_bus_flags(iter, conn,
1225 crtc_state->state);
1226
1227 ret = drm_atomic_bridge_check(iter, crtc_state, conn_state);
1228 if (ret)
1229 return ret;
1230
1231 if (iter == bridge)
1232 break;
1233 }
1234
1235 return 0;
1236}
1237EXPORT_SYMBOL(drm_atomic_bridge_chain_check);
1238
1239/**
1240 * drm_bridge_detect - check if anything is attached to the bridge output
1241 * @bridge: bridge control structure
1242 *
1243 * If the bridge supports output detection, as reported by the
1244 * DRM_BRIDGE_OP_DETECT bridge ops flag, call &drm_bridge_funcs.detect for the
1245 * bridge and return the connection status. Otherwise return
1246 * connector_status_unknown.
1247 *
1248 * RETURNS:
1249 * The detection status on success, or connector_status_unknown if the bridge
1250 * doesn't support output detection.
1251 */
1252enum drm_connector_status drm_bridge_detect(struct drm_bridge *bridge)
1253{
1254 if (!(bridge->ops & DRM_BRIDGE_OP_DETECT))
1255 return connector_status_unknown;
1256
1257 return bridge->funcs->detect(bridge);
1258}
1259EXPORT_SYMBOL_GPL(drm_bridge_detect);
1260
1261/**
1262 * drm_bridge_get_modes - fill all modes currently valid for the sink into the
1263 * @connector
1264 * @bridge: bridge control structure
1265 * @connector: the connector to fill with modes
1266 *
1267 * If the bridge supports output modes retrieval, as reported by the
1268 * DRM_BRIDGE_OP_MODES bridge ops flag, call &drm_bridge_funcs.get_modes to
1269 * fill the connector with all valid modes and return the number of modes
1270 * added. Otherwise return 0.
1271 *
1272 * RETURNS:
1273 * The number of modes added to the connector.
1274 */
1275int drm_bridge_get_modes(struct drm_bridge *bridge,
1276 struct drm_connector *connector)
1277{
1278 if (!(bridge->ops & DRM_BRIDGE_OP_MODES))
1279 return 0;
1280
1281 return bridge->funcs->get_modes(bridge, connector);
1282}
1283EXPORT_SYMBOL_GPL(drm_bridge_get_modes);
1284
1285/**
1286 * drm_bridge_get_edid - get the EDID data of the connected display
1287 * @bridge: bridge control structure
1288 * @connector: the connector to read EDID for
1289 *
1290 * If the bridge supports output EDID retrieval, as reported by the
1291 * DRM_BRIDGE_OP_EDID bridge ops flag, call &drm_bridge_funcs.get_edid to
1292 * get the EDID and return it. Otherwise return NULL.
1293 *
1294 * RETURNS:
1295 * The retrieved EDID on success, or NULL otherwise.
1296 */
1297struct edid *drm_bridge_get_edid(struct drm_bridge *bridge,
1298 struct drm_connector *connector)
1299{
1300 if (!(bridge->ops & DRM_BRIDGE_OP_EDID))
1301 return NULL((void *)0);
1302
1303 return bridge->funcs->get_edid(bridge, connector);
1304}
1305EXPORT_SYMBOL_GPL(drm_bridge_get_edid);
1306
1307/**
1308 * drm_bridge_hpd_enable - enable hot plug detection for the bridge
1309 * @bridge: bridge control structure
1310 * @cb: hot-plug detection callback
1311 * @data: data to be passed to the hot-plug detection callback
1312 *
1313 * Call &drm_bridge_funcs.hpd_enable if implemented and register the given @cb
1314 * and @data as hot plug notification callback. From now on the @cb will be
1315 * called with @data when an output status change is detected by the bridge,
1316 * until hot plug notification gets disabled with drm_bridge_hpd_disable().
1317 *
1318 * Hot plug detection is supported only if the DRM_BRIDGE_OP_HPD flag is set in
1319 * bridge->ops. This function shall not be called when the flag is not set.
1320 *
1321 * Only one hot plug detection callback can be registered at a time, it is an
1322 * error to call this function when hot plug detection is already enabled for
1323 * the bridge.
1324 */
1325void drm_bridge_hpd_enable(struct drm_bridge *bridge,
1326 void (*cb)(void *data,
1327 enum drm_connector_status status),
1328 void *data)
1329{
1330 if (!(bridge->ops & DRM_BRIDGE_OP_HPD))
1331 return;
1332
1333 mutex_lock(&bridge->hpd_mutex)rw_enter_write(&bridge->hpd_mutex);
1334
1335 if (WARN(bridge->hpd_cb, "Hot plug detection already enabled\n")({ int __ret = !!(bridge->hpd_cb); if (__ret) printf("Hot plug detection already enabled\n"
); __builtin_expect(!!(__ret), 0); }))
1336 goto unlock;
1337
1338 bridge->hpd_cb = cb;
1339 bridge->hpd_data = data;
1340
1341 if (bridge->funcs->hpd_enable)
1342 bridge->funcs->hpd_enable(bridge);
1343
1344unlock:
1345 mutex_unlock(&bridge->hpd_mutex)rw_exit_write(&bridge->hpd_mutex);
1346}
1347EXPORT_SYMBOL_GPL(drm_bridge_hpd_enable);
1348
1349/**
1350 * drm_bridge_hpd_disable - disable hot plug detection for the bridge
1351 * @bridge: bridge control structure
1352 *
1353 * Call &drm_bridge_funcs.hpd_disable if implemented and unregister the hot
1354 * plug detection callback previously registered with drm_bridge_hpd_enable().
1355 * Once this function returns the callback will not be called by the bridge
1356 * when an output status change occurs.
1357 *
1358 * Hot plug detection is supported only if the DRM_BRIDGE_OP_HPD flag is set in
1359 * bridge->ops. This function shall not be called when the flag is not set.
1360 */
1361void drm_bridge_hpd_disable(struct drm_bridge *bridge)
1362{
1363 if (!(bridge->ops & DRM_BRIDGE_OP_HPD))
1364 return;
1365
1366 mutex_lock(&bridge->hpd_mutex)rw_enter_write(&bridge->hpd_mutex);
1367 if (bridge->funcs->hpd_disable)
1368 bridge->funcs->hpd_disable(bridge);
1369
1370 bridge->hpd_cb = NULL((void *)0);
1371 bridge->hpd_data = NULL((void *)0);
1372 mutex_unlock(&bridge->hpd_mutex)rw_exit_write(&bridge->hpd_mutex);
1373}
1374EXPORT_SYMBOL_GPL(drm_bridge_hpd_disable);
1375
1376/**
1377 * drm_bridge_hpd_notify - notify hot plug detection events
1378 * @bridge: bridge control structure
1379 * @status: output connection status
1380 *
1381 * Bridge drivers shall call this function to report hot plug events when they
1382 * detect a change in the output status, when hot plug detection has been
1383 * enabled by drm_bridge_hpd_enable().
1384 *
1385 * This function shall be called in a context that can sleep.
1386 */
1387void drm_bridge_hpd_notify(struct drm_bridge *bridge,
1388 enum drm_connector_status status)
1389{
1390 mutex_lock(&bridge->hpd_mutex)rw_enter_write(&bridge->hpd_mutex);
1391 if (bridge->hpd_cb)
1392 bridge->hpd_cb(bridge->hpd_data, status);
1393 mutex_unlock(&bridge->hpd_mutex)rw_exit_write(&bridge->hpd_mutex);
1394}
1395EXPORT_SYMBOL_GPL(drm_bridge_hpd_notify);
1396
1397#ifdef CONFIG_OF
1398/**
1399 * of_drm_find_bridge - find the bridge corresponding to the device node in
1400 * the global bridge list
1401 *
1402 * @np: device node
1403 *
1404 * RETURNS:
1405 * drm_bridge control struct on success, NULL on failure
1406 */
1407struct drm_bridge *of_drm_find_bridge(struct device_node *np)
1408{
1409 struct drm_bridge *bridge;
1410
1411 mutex_lock(&bridge_lock)rw_enter_write(&bridge_lock);
1412
1413 list_for_each_entry(bridge, &bridge_list, list)for (bridge = ({ const __typeof( ((__typeof(*bridge) *)0)->
list ) *__mptr = ((&bridge_list)->next); (__typeof(*bridge
) *)( (char *)__mptr - __builtin_offsetof(__typeof(*bridge), list
) );}); &bridge->list != (&bridge_list); bridge = (
{ const __typeof( ((__typeof(*bridge) *)0)->list ) *__mptr
= (bridge->list.next); (__typeof(*bridge) *)( (char *)__mptr
- __builtin_offsetof(__typeof(*bridge), list) );})) {
1414 if (bridge->of_node == np) {
1415 mutex_unlock(&bridge_lock)rw_exit_write(&bridge_lock);
1416 return bridge;
1417 }
1418 }
1419
1420 mutex_unlock(&bridge_lock)rw_exit_write(&bridge_lock);
1421 return NULL((void *)0);
1422}
1423EXPORT_SYMBOL(of_drm_find_bridge);
1424#endif
1425
1426MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@samsung.com>");
1427MODULE_DESCRIPTION("DRM bridge infrastructure");
1428MODULE_LICENSE("GPL and additional rights");