2 * Copyright (c) 2006-2008 Intel Corporation
3 * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
5 * DRM core CRTC related functions
7 * Permission to use, copy, modify, distribute, and sell this software and its
8 * documentation for any purpose is hereby granted without fee, provided that
9 * the above copyright notice appear in all copies and that both that copyright
10 * notice and this permission notice appear in supporting documentation, and
11 * that the name of the copyright holders not be used in advertising or
12 * publicity pertaining to distribution of the software without specific,
13 * written prior permission. The copyright holders make no representations
14 * about the suitability of this software for any purpose. It is provided "as
15 * is" without express or implied warranty.
17 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
18 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
19 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
20 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
21 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
22 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
27 * Eric Anholt <eric@anholt.net>
28 * Dave Airlie <airlied@linux.ie>
29 * Jesse Barnes <jesse.barnes@intel.com>
32 #include <linux/export.h>
33 #include <linux/moduleparam.h>
35 #include <drm/drm_client.h>
36 #include <drm/drm_crtc.h>
37 #include <drm/drm_edid.h>
38 #include <drm/drm_fb_helper.h>
39 #include <drm/drm_fourcc.h>
40 #include <drm/drm_modeset_helper_vtables.h>
41 #include <drm/drm_print.h>
42 #include <drm/drm_probe_helper.h>
43 #include <drm/drm_sysfs.h>
45 #include "drm_crtc_helper_internal.h"
48 * DOC: output probing helper overview
50 * This library provides some helper code for output probing. It provides an
51 * implementation of the core &drm_connector_funcs.fill_modes interface with
52 * drm_helper_probe_single_connector_modes().
54 * It also provides support for polling connectors with a work item and for
55 * generic hotplug interrupt handling where the driver doesn't or cannot keep
56 * track of a per-connector hpd interrupt.
58 * This helper library can be used independently of the modeset helper library.
59 * Drivers can also overwrite different parts e.g. use their own hotplug
60 * handling code to avoid probing unrelated outputs.
62 * The probe helpers share the function table structures with other display
63 * helper libraries. See &struct drm_connector_helper_funcs for the details.
66 static bool drm_kms_helper_poll
= true;
67 module_param_named(poll
, drm_kms_helper_poll
, bool, 0600);
69 static enum drm_mode_status
70 drm_mode_validate_flag(const struct drm_display_mode
*mode
,
73 if ((mode
->flags
& DRM_MODE_FLAG_INTERLACE
) &&
74 !(flags
& DRM_MODE_FLAG_INTERLACE
))
75 return MODE_NO_INTERLACE
;
77 if ((mode
->flags
& DRM_MODE_FLAG_DBLSCAN
) &&
78 !(flags
& DRM_MODE_FLAG_DBLSCAN
))
79 return MODE_NO_DBLESCAN
;
81 if ((mode
->flags
& DRM_MODE_FLAG_3D_MASK
) &&
82 !(flags
& DRM_MODE_FLAG_3D_MASK
))
83 return MODE_NO_STEREO
;
88 static enum drm_mode_status
89 drm_mode_validate_pipeline(struct drm_display_mode
*mode
,
90 struct drm_connector
*connector
)
92 struct drm_device
*dev
= connector
->dev
;
93 enum drm_mode_status ret
= MODE_OK
;
94 struct drm_encoder
*encoder
;
97 /* Step 1: Validate against connector */
98 ret
= drm_connector_mode_valid(connector
, mode
);
102 /* Step 2: Validate against encoders and crtcs */
103 drm_connector_for_each_possible_encoder(connector
, encoder
, i
) {
104 struct drm_crtc
*crtc
;
106 ret
= drm_encoder_mode_valid(encoder
, mode
);
107 if (ret
!= MODE_OK
) {
108 /* No point in continuing for crtc check as this encoder
109 * will not accept the mode anyway. If all encoders
110 * reject the mode then, at exit, ret will not be
115 ret
= drm_bridge_mode_valid(encoder
->bridge
, mode
);
116 if (ret
!= MODE_OK
) {
117 /* There is also no point in continuing for crtc check
122 drm_for_each_crtc(crtc
, dev
) {
123 if (!drm_encoder_crtc_ok(encoder
, crtc
))
126 ret
= drm_crtc_mode_valid(crtc
, mode
);
127 if (ret
== MODE_OK
) {
128 /* If we get to this point there is at least
129 * one combination of encoder+crtc that works
130 * for this mode. Lets return now. */
139 static int drm_helper_probe_add_cmdline_mode(struct drm_connector
*connector
)
141 struct drm_cmdline_mode
*cmdline_mode
;
142 struct drm_display_mode
*mode
;
144 cmdline_mode
= &connector
->cmdline_mode
;
145 if (!cmdline_mode
->specified
)
148 /* Only add a GTF mode if we find no matching probed modes */
149 list_for_each_entry(mode
, &connector
->probed_modes
, head
) {
150 if (mode
->hdisplay
!= cmdline_mode
->xres
||
151 mode
->vdisplay
!= cmdline_mode
->yres
)
154 if (cmdline_mode
->refresh_specified
) {
155 /* The probed mode's vrefresh is set until later */
156 if (drm_mode_vrefresh(mode
) != cmdline_mode
->refresh
)
163 mode
= drm_mode_create_from_cmdline_mode(connector
->dev
,
168 drm_mode_probed_add(connector
, mode
);
172 enum drm_mode_status
drm_crtc_mode_valid(struct drm_crtc
*crtc
,
173 const struct drm_display_mode
*mode
)
175 const struct drm_crtc_helper_funcs
*crtc_funcs
= crtc
->helper_private
;
177 if (!crtc_funcs
|| !crtc_funcs
->mode_valid
)
180 return crtc_funcs
->mode_valid(crtc
, mode
);
183 enum drm_mode_status
drm_encoder_mode_valid(struct drm_encoder
*encoder
,
184 const struct drm_display_mode
*mode
)
186 const struct drm_encoder_helper_funcs
*encoder_funcs
=
187 encoder
->helper_private
;
189 if (!encoder_funcs
|| !encoder_funcs
->mode_valid
)
192 return encoder_funcs
->mode_valid(encoder
, mode
);
195 enum drm_mode_status
drm_connector_mode_valid(struct drm_connector
*connector
,
196 struct drm_display_mode
*mode
)
198 const struct drm_connector_helper_funcs
*connector_funcs
=
199 connector
->helper_private
;
201 if (!connector_funcs
|| !connector_funcs
->mode_valid
)
204 return connector_funcs
->mode_valid(connector
, mode
);
207 #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
209 * drm_kms_helper_poll_enable - re-enable output polling.
212 * This function re-enables the output polling work, after it has been
213 * temporarily disabled using drm_kms_helper_poll_disable(), for example over
216 * Drivers can call this helper from their device resume implementation. It is
217 * not an error to call this even when output polling isn't enabled.
219 * Note that calls to enable and disable polling must be strictly ordered, which
220 * is automatically the case when they're only call from suspend/resume
223 void drm_kms_helper_poll_enable(struct drm_device
*dev
)
226 struct drm_connector
*connector
;
227 struct drm_connector_list_iter conn_iter
;
228 unsigned long delay
= DRM_OUTPUT_POLL_PERIOD
;
230 if (!dev
->mode_config
.poll_enabled
|| !drm_kms_helper_poll
)
233 drm_connector_list_iter_begin(dev
, &conn_iter
);
234 drm_for_each_connector_iter(connector
, &conn_iter
) {
235 if (connector
->polled
& (DRM_CONNECTOR_POLL_CONNECT
|
236 DRM_CONNECTOR_POLL_DISCONNECT
))
239 drm_connector_list_iter_end(&conn_iter
);
241 if (dev
->mode_config
.delayed_event
) {
245 * Use short (1s) delay to handle the initial delayed event.
246 * This delay should not be needed, but Optimus/nouveau will
247 * fail in a mysterious way if the delayed event is handled as
248 * soon as possible like it is done in
249 * drm_helper_probe_single_connector_modes() in case the poll
250 * was enabled before.
257 schedule_delayed_work(&dev
->mode_config
.output_poll_work
, delay
);
259 EXPORT_SYMBOL(drm_kms_helper_poll_enable
);
261 static enum drm_connector_status
262 drm_helper_probe_detect_ctx(struct drm_connector
*connector
, bool force
)
264 const struct drm_connector_helper_funcs
*funcs
= connector
->helper_private
;
265 struct drm_modeset_acquire_ctx ctx
;
268 drm_modeset_acquire_init(&ctx
, 0);
271 ret
= drm_modeset_lock(&connector
->dev
->mode_config
.connection_mutex
, &ctx
);
273 if (funcs
->detect_ctx
)
274 ret
= funcs
->detect_ctx(connector
, &ctx
, force
);
275 else if (connector
->funcs
->detect
)
276 ret
= connector
->funcs
->detect(connector
, force
);
278 ret
= connector_status_connected
;
281 if (ret
== -EDEADLK
) {
282 drm_modeset_backoff(&ctx
);
286 if (WARN_ON(ret
< 0))
287 ret
= connector_status_unknown
;
289 drm_modeset_drop_locks(&ctx
);
290 drm_modeset_acquire_fini(&ctx
);
296 * drm_helper_probe_detect - probe connector status
297 * @connector: connector to probe
298 * @ctx: acquire_ctx, or NULL to let this function handle locking.
299 * @force: Whether destructive probe operations should be performed.
301 * This function calls the detect callbacks of the connector.
302 * This function returns &drm_connector_status, or
303 * if @ctx is set, it might also return -EDEADLK.
306 drm_helper_probe_detect(struct drm_connector
*connector
,
307 struct drm_modeset_acquire_ctx
*ctx
,
310 const struct drm_connector_helper_funcs
*funcs
= connector
->helper_private
;
311 struct drm_device
*dev
= connector
->dev
;
315 return drm_helper_probe_detect_ctx(connector
, force
);
317 ret
= drm_modeset_lock(&dev
->mode_config
.connection_mutex
, ctx
);
321 if (funcs
->detect_ctx
)
322 return funcs
->detect_ctx(connector
, ctx
, force
);
323 else if (connector
->funcs
->detect
)
324 return connector
->funcs
->detect(connector
, force
);
326 return connector_status_connected
;
328 EXPORT_SYMBOL(drm_helper_probe_detect
);
331 * drm_helper_probe_single_connector_modes - get complete set of display modes
332 * @connector: connector to probe
333 * @maxX: max width for modes
334 * @maxY: max height for modes
336 * Based on the helper callbacks implemented by @connector in struct
337 * &drm_connector_helper_funcs try to detect all valid modes. Modes will first
338 * be added to the connector's probed_modes list, then culled (based on validity
339 * and the @maxX, @maxY parameters) and put into the normal modes list.
341 * Intended to be used as a generic implementation of the
342 * &drm_connector_funcs.fill_modes() vfunc for drivers that use the CRTC helpers
343 * for output mode filtering and detection.
345 * The basic procedure is as follows
347 * 1. All modes currently on the connector's modes list are marked as stale
349 * 2. New modes are added to the connector's probed_modes list with
350 * drm_mode_probed_add(). New modes start their life with status as OK.
351 * Modes are added from a single source using the following priority order.
353 * - &drm_connector_helper_funcs.get_modes vfunc
354 * - if the connector status is connector_status_connected, standard
355 * VESA DMT modes up to 1024x768 are automatically added
356 * (drm_add_modes_noedid())
358 * Finally modes specified via the kernel command line (video=...) are
359 * added in addition to what the earlier probes produced
360 * (drm_helper_probe_add_cmdline_mode()). These modes are generated
361 * using the VESA GTF/CVT formulas.
363 * 3. Modes are moved from the probed_modes list to the modes list. Potential
364 * duplicates are merged together (see drm_connector_list_update()).
365 * After this step the probed_modes list will be empty again.
367 * 4. Any non-stale mode on the modes list then undergoes validation
369 * - drm_mode_validate_basic() performs basic sanity checks
370 * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
372 * - drm_mode_validate_flag() checks the modes against basic connector
373 * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed)
374 * - the optional &drm_connector_helper_funcs.mode_valid helper can perform
375 * driver and/or sink specific checks
376 * - the optional &drm_crtc_helper_funcs.mode_valid,
377 * &drm_bridge_funcs.mode_valid and &drm_encoder_helper_funcs.mode_valid
378 * helpers can perform driver and/or source specific checks which are also
379 * enforced by the modeset/atomic helpers
381 * 5. Any mode whose status is not OK is pruned from the connector's modes list,
382 * accompanied by a debug message indicating the reason for the mode's
383 * rejection (see drm_mode_prune_invalid()).
386 * The number of modes found on @connector.
388 int drm_helper_probe_single_connector_modes(struct drm_connector
*connector
,
389 uint32_t maxX
, uint32_t maxY
)
391 struct drm_device
*dev
= connector
->dev
;
392 struct drm_display_mode
*mode
;
393 const struct drm_connector_helper_funcs
*connector_funcs
=
394 connector
->helper_private
;
397 bool verbose_prune
= true;
398 enum drm_connector_status old_status
;
399 struct drm_modeset_acquire_ctx ctx
;
401 WARN_ON(!mutex_is_locked(&dev
->mode_config
.mutex
));
403 drm_modeset_acquire_init(&ctx
, 0);
405 DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector
->base
.id
,
409 ret
= drm_modeset_lock(&dev
->mode_config
.connection_mutex
, &ctx
);
410 if (ret
== -EDEADLK
) {
411 drm_modeset_backoff(&ctx
);
416 /* set all old modes to the stale state */
417 list_for_each_entry(mode
, &connector
->modes
, head
)
418 mode
->status
= MODE_STALE
;
420 old_status
= connector
->status
;
422 if (connector
->force
) {
423 if (connector
->force
== DRM_FORCE_ON
||
424 connector
->force
== DRM_FORCE_ON_DIGITAL
)
425 connector
->status
= connector_status_connected
;
427 connector
->status
= connector_status_disconnected
;
428 if (connector
->funcs
->force
)
429 connector
->funcs
->force(connector
);
431 ret
= drm_helper_probe_detect(connector
, &ctx
, true);
433 if (ret
== -EDEADLK
) {
434 drm_modeset_backoff(&ctx
);
436 } else if (WARN(ret
< 0, "Invalid return value %i for connector detection\n", ret
))
437 ret
= connector_status_unknown
;
439 connector
->status
= ret
;
443 * Normally either the driver's hpd code or the poll loop should
444 * pick up any changes and fire the hotplug event. But if
445 * userspace sneaks in a probe, we might miss a change. Hence
446 * check here, and if anything changed start the hotplug code.
448 if (old_status
!= connector
->status
) {
449 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
452 drm_get_connector_status_name(old_status
),
453 drm_get_connector_status_name(connector
->status
));
456 * The hotplug event code might call into the fb
457 * helpers, and so expects that we do not hold any
458 * locks. Fire up the poll struct instead, it will
459 * disable itself again.
461 dev
->mode_config
.delayed_event
= true;
462 if (dev
->mode_config
.poll_enabled
)
463 schedule_delayed_work(&dev
->mode_config
.output_poll_work
,
467 /* Re-enable polling in case the global poll config changed. */
468 if (drm_kms_helper_poll
!= dev
->mode_config
.poll_running
)
469 drm_kms_helper_poll_enable(dev
);
471 dev
->mode_config
.poll_running
= drm_kms_helper_poll
;
473 if (connector
->status
== connector_status_disconnected
) {
474 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
475 connector
->base
.id
, connector
->name
);
476 drm_connector_update_edid_property(connector
, NULL
);
477 verbose_prune
= false;
481 count
= (*connector_funcs
->get_modes
)(connector
);
484 * Fallback for when DDC probe failed in drm_get_edid() and thus skipped
485 * override/firmware EDID.
487 if (count
== 0 && connector
->status
== connector_status_connected
)
488 count
= drm_add_override_edid_modes(connector
);
490 if (count
== 0 && connector
->status
== connector_status_connected
)
491 count
= drm_add_modes_noedid(connector
, 1024, 768);
492 count
+= drm_helper_probe_add_cmdline_mode(connector
);
496 drm_connector_list_update(connector
);
498 if (connector
->interlace_allowed
)
499 mode_flags
|= DRM_MODE_FLAG_INTERLACE
;
500 if (connector
->doublescan_allowed
)
501 mode_flags
|= DRM_MODE_FLAG_DBLSCAN
;
502 if (connector
->stereo_allowed
)
503 mode_flags
|= DRM_MODE_FLAG_3D_MASK
;
505 list_for_each_entry(mode
, &connector
->modes
, head
) {
506 if (mode
->status
== MODE_OK
)
507 mode
->status
= drm_mode_validate_driver(dev
, mode
);
509 if (mode
->status
== MODE_OK
)
510 mode
->status
= drm_mode_validate_size(mode
, maxX
, maxY
);
512 if (mode
->status
== MODE_OK
)
513 mode
->status
= drm_mode_validate_flag(mode
, mode_flags
);
515 if (mode
->status
== MODE_OK
)
516 mode
->status
= drm_mode_validate_pipeline(mode
,
519 if (mode
->status
== MODE_OK
)
520 mode
->status
= drm_mode_validate_ycbcr420(mode
,
525 drm_mode_prune_invalid(dev
, &connector
->modes
, verbose_prune
);
527 drm_modeset_drop_locks(&ctx
);
528 drm_modeset_acquire_fini(&ctx
);
530 if (list_empty(&connector
->modes
))
533 list_for_each_entry(mode
, &connector
->modes
, head
)
534 mode
->vrefresh
= drm_mode_vrefresh(mode
);
536 drm_mode_sort(&connector
->modes
);
538 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector
->base
.id
,
540 list_for_each_entry(mode
, &connector
->modes
, head
) {
541 drm_mode_set_crtcinfo(mode
, CRTC_INTERLACE_HALVE_V
);
542 drm_mode_debug_printmodeline(mode
);
547 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes
);
550 * drm_kms_helper_hotplug_event - fire off KMS hotplug events
551 * @dev: drm_device whose connector state changed
553 * This function fires off the uevent for userspace and also calls the
554 * output_poll_changed function, which is most commonly used to inform the fbdev
555 * emulation code and allow it to update the fbcon output configuration.
557 * Drivers should call this from their hotplug handling code when a change is
558 * detected. Note that this function does not do any output detection of its
559 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
562 * This function must be called from process context with no mode
563 * setting locks held.
565 void drm_kms_helper_hotplug_event(struct drm_device
*dev
)
567 /* send a uevent + call fbdev */
568 drm_sysfs_hotplug_event(dev
);
569 if (dev
->mode_config
.funcs
->output_poll_changed
)
570 dev
->mode_config
.funcs
->output_poll_changed(dev
);
572 drm_client_dev_hotplug(dev
);
574 EXPORT_SYMBOL(drm_kms_helper_hotplug_event
);
576 static void output_poll_execute(struct work_struct
*work
)
578 struct delayed_work
*delayed_work
= to_delayed_work(work
);
579 struct drm_device
*dev
= container_of(delayed_work
, struct drm_device
, mode_config
.output_poll_work
);
580 struct drm_connector
*connector
;
581 struct drm_connector_list_iter conn_iter
;
582 enum drm_connector_status old_status
;
583 bool repoll
= false, changed
;
585 if (!dev
->mode_config
.poll_enabled
)
588 /* Pick up any changes detected by the probe functions. */
589 changed
= dev
->mode_config
.delayed_event
;
590 dev
->mode_config
.delayed_event
= false;
592 if (!drm_kms_helper_poll
)
595 if (!mutex_trylock(&dev
->mode_config
.mutex
)) {
600 drm_connector_list_iter_begin(dev
, &conn_iter
);
601 drm_for_each_connector_iter(connector
, &conn_iter
) {
602 /* Ignore forced connectors. */
603 if (connector
->force
)
606 /* Ignore HPD capable connectors and connectors where we don't
607 * want any hotplug detection at all for polling. */
608 if (!connector
->polled
|| connector
->polled
== DRM_CONNECTOR_POLL_HPD
)
611 old_status
= connector
->status
;
612 /* if we are connected and don't want to poll for disconnect
614 if (old_status
== connector_status_connected
&&
615 !(connector
->polled
& DRM_CONNECTOR_POLL_DISCONNECT
))
620 connector
->status
= drm_helper_probe_detect(connector
, NULL
, false);
621 if (old_status
!= connector
->status
) {
622 const char *old
, *new;
625 * The poll work sets force=false when calling detect so
626 * that drivers can avoid to do disruptive tests (e.g.
627 * when load detect cycles could cause flickering on
628 * other, running displays). This bears the risk that we
629 * flip-flop between unknown here in the poll work and
630 * the real state when userspace forces a full detect
631 * call after receiving a hotplug event due to this
634 * Hence clamp an unknown detect status to the old
637 if (connector
->status
== connector_status_unknown
) {
638 connector
->status
= old_status
;
642 old
= drm_get_connector_status_name(old_status
);
643 new = drm_get_connector_status_name(connector
->status
);
645 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
646 "status updated from %s to %s\n",
654 drm_connector_list_iter_end(&conn_iter
);
656 mutex_unlock(&dev
->mode_config
.mutex
);
660 drm_kms_helper_hotplug_event(dev
);
663 schedule_delayed_work(delayed_work
, DRM_OUTPUT_POLL_PERIOD
);
667 * drm_kms_helper_is_poll_worker - is %current task an output poll worker?
669 * Determine if %current task is an output poll worker. This can be used
670 * to select distinct code paths for output polling versus other contexts.
672 * One use case is to avoid a deadlock between the output poll worker and
673 * the autosuspend worker wherein the latter waits for polling to finish
674 * upon calling drm_kms_helper_poll_disable(), while the former waits for
675 * runtime suspend to finish upon calling pm_runtime_get_sync() in a
676 * connector ->detect hook.
678 bool drm_kms_helper_is_poll_worker(void)
680 struct work_struct
*work
= current_work();
682 return work
&& work
->func
== output_poll_execute
;
684 EXPORT_SYMBOL(drm_kms_helper_is_poll_worker
);
687 * drm_kms_helper_poll_disable - disable output polling
690 * This function disables the output polling work.
692 * Drivers can call this helper from their device suspend implementation. It is
693 * not an error to call this even when output polling isn't enabled or already
694 * disabled. Polling is re-enabled by calling drm_kms_helper_poll_enable().
696 * Note that calls to enable and disable polling must be strictly ordered, which
697 * is automatically the case when they're only call from suspend/resume
700 void drm_kms_helper_poll_disable(struct drm_device
*dev
)
702 if (!dev
->mode_config
.poll_enabled
)
704 cancel_delayed_work_sync(&dev
->mode_config
.output_poll_work
);
706 EXPORT_SYMBOL(drm_kms_helper_poll_disable
);
709 * drm_kms_helper_poll_init - initialize and enable output polling
712 * This function intializes and then also enables output polling support for
713 * @dev. Drivers which do not have reliable hotplug support in hardware can use
714 * this helper infrastructure to regularly poll such connectors for changes in
715 * their connection state.
717 * Drivers can control which connectors are polled by setting the
718 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
719 * connectors where probing live outputs can result in visual distortion drivers
720 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
721 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
722 * completely ignored by the polling logic.
724 * Note that a connector can be both polled and probed from the hotplug handler,
725 * in case the hotplug interrupt is known to be unreliable.
727 void drm_kms_helper_poll_init(struct drm_device
*dev
)
729 INIT_DELAYED_WORK(&dev
->mode_config
.output_poll_work
, output_poll_execute
);
730 dev
->mode_config
.poll_enabled
= true;
732 drm_kms_helper_poll_enable(dev
);
734 EXPORT_SYMBOL(drm_kms_helper_poll_init
);
737 * drm_kms_helper_poll_fini - disable output polling and clean it up
740 void drm_kms_helper_poll_fini(struct drm_device
*dev
)
742 if (!dev
->mode_config
.poll_enabled
)
745 dev
->mode_config
.poll_enabled
= false;
746 cancel_delayed_work_sync(&dev
->mode_config
.output_poll_work
);
748 EXPORT_SYMBOL(drm_kms_helper_poll_fini
);
751 * drm_helper_hpd_irq_event - hotplug processing
754 * Drivers can use this helper function to run a detect cycle on all connectors
755 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
756 * other connectors are ignored, which is useful to avoid reprobing fixed
759 * This helper function is useful for drivers which can't or don't track hotplug
760 * interrupts for each connector.
762 * Drivers which support hotplug interrupts for each connector individually and
763 * which have a more fine-grained detect logic should bypass this code and
764 * directly call drm_kms_helper_hotplug_event() in case the connector state
767 * This function must be called from process context with no mode
768 * setting locks held.
770 * Note that a connector can be both polled and probed from the hotplug handler,
771 * in case the hotplug interrupt is known to be unreliable.
773 bool drm_helper_hpd_irq_event(struct drm_device
*dev
)
775 struct drm_connector
*connector
;
776 struct drm_connector_list_iter conn_iter
;
777 enum drm_connector_status old_status
;
778 bool changed
= false;
780 if (!dev
->mode_config
.poll_enabled
)
783 mutex_lock(&dev
->mode_config
.mutex
);
784 drm_connector_list_iter_begin(dev
, &conn_iter
);
785 drm_for_each_connector_iter(connector
, &conn_iter
) {
786 /* Only handle HPD capable connectors. */
787 if (!(connector
->polled
& DRM_CONNECTOR_POLL_HPD
))
790 old_status
= connector
->status
;
792 connector
->status
= drm_helper_probe_detect(connector
, NULL
, false);
793 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
796 drm_get_connector_status_name(old_status
),
797 drm_get_connector_status_name(connector
->status
));
798 if (old_status
!= connector
->status
)
801 drm_connector_list_iter_end(&conn_iter
);
802 mutex_unlock(&dev
->mode_config
.mutex
);
805 drm_kms_helper_hotplug_event(dev
);
809 EXPORT_SYMBOL(drm_helper_hpd_irq_event
);