1 /*
2 * Copyright (c) 2006-2008 Intel Corporation
3 * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
4 *
5 * DRM core CRTC related functions
6 *
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.
16 *
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
23 * OF THIS SOFTWARE.
24 *
25 * Authors:
26 * Keith Packard
27 * Eric Anholt <eric@anholt.net>
28 * Dave Airlie <airlied@linux.ie>
29 * Jesse Barnes <jesse.barnes@intel.com>
30 */
31
32 #include <linux/export.h>
33 #include <linux/moduleparam.h>
34
35 #include <drm/drmP.h>
36 #include <drm/drm_crtc.h>
37 #include <drm/drm_fourcc.h>
38 #include <drm/drm_crtc_helper.h>
39 #include <drm/drm_fb_helper.h>
40 #include <drm/drm_edid.h>
41 #include <drm/drm_modeset_helper_vtables.h>
42
43 #include "drm_crtc_helper_internal.h"
44
45 /**
46 * DOC: output probing helper overview
47 *
48 * This library provides some helper code for output probing. It provides an
49 * implementation of the core &drm_connector_funcs.fill_modes interface with
50 * drm_helper_probe_single_connector_modes().
51 *
52 * It also provides support for polling connectors with a work item and for
53 * generic hotplug interrupt handling where the driver doesn't or cannot keep
54 * track of a per-connector hpd interrupt.
55 *
56 * This helper library can be used independently of the modeset helper library.
57 * Drivers can also overwrite different parts e.g. use their own hotplug
58 * handling code to avoid probing unrelated outputs.
59 *
60 * The probe helpers share the function table structures with other display
61 * helper libraries. See &struct drm_connector_helper_funcs for the details.
62 */
63
64 static bool drm_kms_helper_poll = true;
65 module_param_named(poll, drm_kms_helper_poll, bool, 0600);
66
67 static enum drm_mode_status
drm_mode_validate_flag(const struct drm_display_mode * mode,int flags)68 drm_mode_validate_flag(const struct drm_display_mode *mode,
69 int flags)
70 {
71 if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
72 !(flags & DRM_MODE_FLAG_INTERLACE))
73 return MODE_NO_INTERLACE;
74
75 if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
76 !(flags & DRM_MODE_FLAG_DBLSCAN))
77 return MODE_NO_DBLESCAN;
78
79 if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
80 !(flags & DRM_MODE_FLAG_3D_MASK))
81 return MODE_NO_STEREO;
82
83 return MODE_OK;
84 }
85
86 static enum drm_mode_status
drm_mode_validate_pipeline(struct drm_display_mode * mode,struct drm_connector * connector)87 drm_mode_validate_pipeline(struct drm_display_mode *mode,
88 struct drm_connector *connector)
89 {
90 struct drm_device *dev = connector->dev;
91 uint32_t *ids = connector->encoder_ids;
92 enum drm_mode_status ret = MODE_OK;
93 unsigned int i;
94
95 /* Step 1: Validate against connector */
96 ret = drm_connector_mode_valid(connector, mode);
97 if (ret != MODE_OK)
98 return ret;
99
100 /* Step 2: Validate against encoders and crtcs */
101 for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) {
102 struct drm_encoder *encoder = drm_encoder_find(dev, NULL, ids[i]);
103 struct drm_crtc *crtc;
104
105 if (!encoder)
106 continue;
107
108 ret = drm_encoder_mode_valid(encoder, mode);
109 if (ret != MODE_OK) {
110 /* No point in continuing for crtc check as this encoder
111 * will not accept the mode anyway. If all encoders
112 * reject the mode then, at exit, ret will not be
113 * MODE_OK. */
114 continue;
115 }
116
117 ret = drm_bridge_mode_valid(encoder->bridge, mode);
118 if (ret != MODE_OK) {
119 /* There is also no point in continuing for crtc check
120 * here. */
121 continue;
122 }
123
124 drm_for_each_crtc(crtc, dev) {
125 if (!drm_encoder_crtc_ok(encoder, crtc))
126 continue;
127
128 ret = drm_crtc_mode_valid(crtc, mode);
129 if (ret == MODE_OK) {
130 /* If we get to this point there is at least
131 * one combination of encoder+crtc that works
132 * for this mode. Lets return now. */
133 return ret;
134 }
135 }
136 }
137
138 return ret;
139 }
140
drm_helper_probe_add_cmdline_mode(struct drm_connector * connector)141 static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
142 {
143 struct drm_cmdline_mode *cmdline_mode;
144 struct drm_display_mode *mode;
145
146 cmdline_mode = &connector->cmdline_mode;
147 if (!cmdline_mode->specified)
148 return 0;
149
150 /* Only add a GTF mode if we find no matching probed modes */
151 list_for_each_entry(mode, &connector->probed_modes, head) {
152 if (mode->hdisplay != cmdline_mode->xres ||
153 mode->vdisplay != cmdline_mode->yres)
154 continue;
155
156 if (cmdline_mode->refresh_specified) {
157 /* The probed mode's vrefresh is set until later */
158 if (drm_mode_vrefresh(mode) != cmdline_mode->refresh)
159 continue;
160 }
161
162 return 0;
163 }
164
165 mode = drm_mode_create_from_cmdline_mode(connector->dev,
166 cmdline_mode);
167 if (mode == NULL)
168 return 0;
169
170 drm_mode_probed_add(connector, mode);
171 return 1;
172 }
173
drm_crtc_mode_valid(struct drm_crtc * crtc,const struct drm_display_mode * mode)174 enum drm_mode_status drm_crtc_mode_valid(struct drm_crtc *crtc,
175 const struct drm_display_mode *mode)
176 {
177 const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
178
179 if (!crtc_funcs || !crtc_funcs->mode_valid)
180 return MODE_OK;
181
182 return crtc_funcs->mode_valid(crtc, mode);
183 }
184
drm_encoder_mode_valid(struct drm_encoder * encoder,const struct drm_display_mode * mode)185 enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder,
186 const struct drm_display_mode *mode)
187 {
188 const struct drm_encoder_helper_funcs *encoder_funcs =
189 encoder->helper_private;
190
191 if (!encoder_funcs || !encoder_funcs->mode_valid)
192 return MODE_OK;
193
194 return encoder_funcs->mode_valid(encoder, mode);
195 }
196
drm_connector_mode_valid(struct drm_connector * connector,struct drm_display_mode * mode)197 enum drm_mode_status drm_connector_mode_valid(struct drm_connector *connector,
198 struct drm_display_mode *mode)
199 {
200 const struct drm_connector_helper_funcs *connector_funcs =
201 connector->helper_private;
202
203 if (!connector_funcs || !connector_funcs->mode_valid)
204 return MODE_OK;
205
206 return connector_funcs->mode_valid(connector, mode);
207 }
208
209 #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
210 /**
211 * drm_kms_helper_poll_enable - re-enable output polling.
212 * @dev: drm_device
213 *
214 * This function re-enables the output polling work, after it has been
215 * temporarily disabled using drm_kms_helper_poll_disable(), for example over
216 * suspend/resume.
217 *
218 * Drivers can call this helper from their device resume implementation. It is
219 * an error to call this when the output polling support has not yet been set
220 * up.
221 *
222 * Note that calls to enable and disable polling must be strictly ordered, which
223 * is automatically the case when they're only call from suspend/resume
224 * callbacks.
225 */
drm_kms_helper_poll_enable(struct drm_device * dev)226 void drm_kms_helper_poll_enable(struct drm_device *dev)
227 {
228 bool poll = false;
229 struct drm_connector *connector;
230 struct drm_connector_list_iter conn_iter;
231 unsigned long delay = DRM_OUTPUT_POLL_PERIOD;
232
233 if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
234 return;
235
236 drm_connector_list_iter_begin(dev, &conn_iter);
237 drm_for_each_connector_iter(connector, &conn_iter) {
238 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
239 DRM_CONNECTOR_POLL_DISCONNECT))
240 poll = true;
241 }
242 drm_connector_list_iter_end(&conn_iter);
243
244 if (dev->mode_config.delayed_event) {
245 /*
246 * FIXME:
247 *
248 * Use short (1s) delay to handle the initial delayed event.
249 * This delay should not be needed, but Optimus/nouveau will
250 * fail in a mysterious way if the delayed event is handled as
251 * soon as possible like it is done in
252 * drm_helper_probe_single_connector_modes() in case the poll
253 * was enabled before.
254 */
255 poll = true;
256 delay = HZ;
257 }
258
259 if (poll)
260 schedule_delayed_work(&dev->mode_config.output_poll_work, delay);
261 }
262 EXPORT_SYMBOL(drm_kms_helper_poll_enable);
263
264 static enum drm_connector_status
drm_helper_probe_detect_ctx(struct drm_connector * connector,bool force)265 drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force)
266 {
267 const struct drm_connector_helper_funcs *funcs = connector->helper_private;
268 struct drm_modeset_acquire_ctx ctx;
269 int ret;
270
271 drm_modeset_acquire_init(&ctx, 0);
272
273 retry:
274 ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, &ctx);
275 if (!ret) {
276 if (funcs->detect_ctx)
277 ret = funcs->detect_ctx(connector, &ctx, force);
278 else if (connector->funcs->detect)
279 ret = connector->funcs->detect(connector, force);
280 else
281 ret = connector_status_connected;
282 }
283
284 if (ret == -EDEADLK) {
285 drm_modeset_backoff(&ctx);
286 goto retry;
287 }
288
289 if (WARN_ON(ret < 0))
290 ret = connector_status_unknown;
291
292 drm_modeset_drop_locks(&ctx);
293 drm_modeset_acquire_fini(&ctx);
294
295 return ret;
296 }
297
298 /**
299 * drm_helper_probe_detect - probe connector status
300 * @connector: connector to probe
301 * @ctx: acquire_ctx, or NULL to let this function handle locking.
302 * @force: Whether destructive probe operations should be performed.
303 *
304 * This function calls the detect callbacks of the connector.
305 * This function returns &drm_connector_status, or
306 * if @ctx is set, it might also return -EDEADLK.
307 */
308 int
drm_helper_probe_detect(struct drm_connector * connector,struct drm_modeset_acquire_ctx * ctx,bool force)309 drm_helper_probe_detect(struct drm_connector *connector,
310 struct drm_modeset_acquire_ctx *ctx,
311 bool force)
312 {
313 const struct drm_connector_helper_funcs *funcs = connector->helper_private;
314 struct drm_device *dev = connector->dev;
315 int ret;
316
317 if (!ctx)
318 return drm_helper_probe_detect_ctx(connector, force);
319
320 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
321 if (ret)
322 return ret;
323
324 if (funcs->detect_ctx)
325 return funcs->detect_ctx(connector, ctx, force);
326 else if (connector->funcs->detect)
327 return connector->funcs->detect(connector, force);
328 else
329 return connector_status_connected;
330 }
331 EXPORT_SYMBOL(drm_helper_probe_detect);
332
333 /**
334 * drm_helper_probe_single_connector_modes - get complete set of display modes
335 * @connector: connector to probe
336 * @maxX: max width for modes
337 * @maxY: max height for modes
338 *
339 * Based on the helper callbacks implemented by @connector in struct
340 * &drm_connector_helper_funcs try to detect all valid modes. Modes will first
341 * be added to the connector's probed_modes list, then culled (based on validity
342 * and the @maxX, @maxY parameters) and put into the normal modes list.
343 *
344 * Intended to be used as a generic implementation of the
345 * &drm_connector_funcs.fill_modes() vfunc for drivers that use the CRTC helpers
346 * for output mode filtering and detection.
347 *
348 * The basic procedure is as follows
349 *
350 * 1. All modes currently on the connector's modes list are marked as stale
351 *
352 * 2. New modes are added to the connector's probed_modes list with
353 * drm_mode_probed_add(). New modes start their life with status as OK.
354 * Modes are added from a single source using the following priority order.
355 *
356 * - &drm_connector_helper_funcs.get_modes vfunc
357 * - if the connector status is connector_status_connected, standard
358 * VESA DMT modes up to 1024x768 are automatically added
359 * (drm_add_modes_noedid())
360 *
361 * Finally modes specified via the kernel command line (video=...) are
362 * added in addition to what the earlier probes produced
363 * (drm_helper_probe_add_cmdline_mode()). These modes are generated
364 * using the VESA GTF/CVT formulas.
365 *
366 * 3. Modes are moved from the probed_modes list to the modes list. Potential
367 * duplicates are merged together (see drm_mode_connector_list_update()).
368 * After this step the probed_modes list will be empty again.
369 *
370 * 4. Any non-stale mode on the modes list then undergoes validation
371 *
372 * - drm_mode_validate_basic() performs basic sanity checks
373 * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
374 * (if specified)
375 * - drm_mode_validate_flag() checks the modes against basic connector
376 * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed)
377 * - the optional &drm_connector_helper_funcs.mode_valid helper can perform
378 * driver and/or sink specific checks
379 * - the optional &drm_crtc_helper_funcs.mode_valid,
380 * &drm_bridge_funcs.mode_valid and &drm_encoder_helper_funcs.mode_valid
381 * helpers can perform driver and/or source specific checks which are also
382 * enforced by the modeset/atomic helpers
383 *
384 * 5. Any mode whose status is not OK is pruned from the connector's modes list,
385 * accompanied by a debug message indicating the reason for the mode's
386 * rejection (see drm_mode_prune_invalid()).
387 *
388 * Returns:
389 * The number of modes found on @connector.
390 */
drm_helper_probe_single_connector_modes(struct drm_connector * connector,uint32_t maxX,uint32_t maxY)391 int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
392 uint32_t maxX, uint32_t maxY)
393 {
394 struct drm_device *dev = connector->dev;
395 struct drm_display_mode *mode;
396 const struct drm_connector_helper_funcs *connector_funcs =
397 connector->helper_private;
398 int count = 0, ret;
399 int mode_flags = 0;
400 bool verbose_prune = true;
401 enum drm_connector_status old_status;
402 struct drm_modeset_acquire_ctx ctx;
403
404 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
405
406 drm_modeset_acquire_init(&ctx, 0);
407
408 DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
409 connector->name);
410
411 retry:
412 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, &ctx);
413 if (ret == -EDEADLK) {
414 drm_modeset_backoff(&ctx);
415 goto retry;
416 } else
417 WARN_ON(ret < 0);
418
419 /* set all old modes to the stale state */
420 list_for_each_entry(mode, &connector->modes, head)
421 mode->status = MODE_STALE;
422
423 old_status = connector->status;
424
425 if (connector->force) {
426 if (connector->force == DRM_FORCE_ON ||
427 connector->force == DRM_FORCE_ON_DIGITAL)
428 connector->status = connector_status_connected;
429 else
430 connector->status = connector_status_disconnected;
431 if (connector->funcs->force)
432 connector->funcs->force(connector);
433 } else {
434 ret = drm_helper_probe_detect(connector, &ctx, true);
435
436 if (ret == -EDEADLK) {
437 drm_modeset_backoff(&ctx);
438 goto retry;
439 } else if (WARN(ret < 0, "Invalid return value %i for connector detection\n", ret))
440 ret = connector_status_unknown;
441
442 connector->status = ret;
443 }
444
445 /*
446 * Normally either the driver's hpd code or the poll loop should
447 * pick up any changes and fire the hotplug event. But if
448 * userspace sneaks in a probe, we might miss a change. Hence
449 * check here, and if anything changed start the hotplug code.
450 */
451 if (old_status != connector->status) {
452 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
453 connector->base.id,
454 connector->name,
455 drm_get_connector_status_name(old_status),
456 drm_get_connector_status_name(connector->status));
457
458 /*
459 * The hotplug event code might call into the fb
460 * helpers, and so expects that we do not hold any
461 * locks. Fire up the poll struct instead, it will
462 * disable itself again.
463 */
464 dev->mode_config.delayed_event = true;
465 if (dev->mode_config.poll_enabled)
466 schedule_delayed_work(&dev->mode_config.output_poll_work,
467 0);
468 }
469
470 /* Re-enable polling in case the global poll config changed. */
471 if (drm_kms_helper_poll != dev->mode_config.poll_running)
472 drm_kms_helper_poll_enable(dev);
473
474 dev->mode_config.poll_running = drm_kms_helper_poll;
475
476 if (connector->status == connector_status_disconnected) {
477 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
478 connector->base.id, connector->name);
479 drm_mode_connector_update_edid_property(connector, NULL);
480 verbose_prune = false;
481 goto prune;
482 }
483
484 count = (*connector_funcs->get_modes)(connector);
485
486 if (count == 0 && connector->status == connector_status_connected)
487 count = drm_add_modes_noedid(connector, 1024, 768);
488 count += drm_helper_probe_add_cmdline_mode(connector);
489 if (count == 0)
490 goto prune;
491
492 drm_mode_connector_list_update(connector);
493
494 if (connector->interlace_allowed)
495 mode_flags |= DRM_MODE_FLAG_INTERLACE;
496 if (connector->doublescan_allowed)
497 mode_flags |= DRM_MODE_FLAG_DBLSCAN;
498 if (connector->stereo_allowed)
499 mode_flags |= DRM_MODE_FLAG_3D_MASK;
500
501 list_for_each_entry(mode, &connector->modes, head) {
502 if (mode->status == MODE_OK)
503 mode->status = drm_mode_validate_basic(mode);
504
505 if (mode->status == MODE_OK)
506 mode->status = drm_mode_validate_size(mode, maxX, maxY);
507
508 if (mode->status == MODE_OK)
509 mode->status = drm_mode_validate_flag(mode, mode_flags);
510
511 if (mode->status == MODE_OK)
512 mode->status = drm_mode_validate_pipeline(mode,
513 connector);
514
515 if (mode->status == MODE_OK)
516 mode->status = drm_mode_validate_ycbcr420(mode,
517 connector);
518 }
519
520 prune:
521 drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
522
523 drm_modeset_drop_locks(&ctx);
524 drm_modeset_acquire_fini(&ctx);
525
526 if (list_empty(&connector->modes))
527 return 0;
528
529 list_for_each_entry(mode, &connector->modes, head)
530 mode->vrefresh = drm_mode_vrefresh(mode);
531
532 drm_mode_sort(&connector->modes);
533
534 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
535 connector->name);
536 list_for_each_entry(mode, &connector->modes, head) {
537 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
538 drm_mode_debug_printmodeline(mode);
539 }
540
541 return count;
542 }
543 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
544
545 /**
546 * drm_kms_helper_hotplug_event - fire off KMS hotplug events
547 * @dev: drm_device whose connector state changed
548 *
549 * This function fires off the uevent for userspace and also calls the
550 * output_poll_changed function, which is most commonly used to inform the fbdev
551 * emulation code and allow it to update the fbcon output configuration.
552 *
553 * Drivers should call this from their hotplug handling code when a change is
554 * detected. Note that this function does not do any output detection of its
555 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
556 * driver already.
557 *
558 * This function must be called from process context with no mode
559 * setting locks held.
560 */
drm_kms_helper_hotplug_event(struct drm_device * dev)561 void drm_kms_helper_hotplug_event(struct drm_device *dev)
562 {
563 /* send a uevent + call fbdev */
564 drm_sysfs_hotplug_event(dev);
565 if (dev->mode_config.funcs->output_poll_changed)
566 dev->mode_config.funcs->output_poll_changed(dev);
567 }
568 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
569
output_poll_execute(struct work_struct * work)570 static void output_poll_execute(struct work_struct *work)
571 {
572 struct delayed_work *delayed_work = to_delayed_work(work);
573 struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
574 struct drm_connector *connector;
575 struct drm_connector_list_iter conn_iter;
576 enum drm_connector_status old_status;
577 bool repoll = false, changed;
578
579 /* Pick up any changes detected by the probe functions. */
580 changed = dev->mode_config.delayed_event;
581 dev->mode_config.delayed_event = false;
582
583 if (!drm_kms_helper_poll)
584 goto out;
585
586 if (!mutex_trylock(&dev->mode_config.mutex)) {
587 repoll = true;
588 goto out;
589 }
590
591 drm_connector_list_iter_begin(dev, &conn_iter);
592 drm_for_each_connector_iter(connector, &conn_iter) {
593 /* Ignore forced connectors. */
594 if (connector->force)
595 continue;
596
597 /* Ignore HPD capable connectors and connectors where we don't
598 * want any hotplug detection at all for polling. */
599 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
600 continue;
601
602 old_status = connector->status;
603 /* if we are connected and don't want to poll for disconnect
604 skip it */
605 if (old_status == connector_status_connected &&
606 !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
607 continue;
608
609 repoll = true;
610
611 connector->status = drm_helper_probe_detect(connector, NULL, false);
612 if (old_status != connector->status) {
613 const char *old, *new;
614
615 /*
616 * The poll work sets force=false when calling detect so
617 * that drivers can avoid to do disruptive tests (e.g.
618 * when load detect cycles could cause flickering on
619 * other, running displays). This bears the risk that we
620 * flip-flop between unknown here in the poll work and
621 * the real state when userspace forces a full detect
622 * call after receiving a hotplug event due to this
623 * change.
624 *
625 * Hence clamp an unknown detect status to the old
626 * value.
627 */
628 if (connector->status == connector_status_unknown) {
629 connector->status = old_status;
630 continue;
631 }
632
633 old = drm_get_connector_status_name(old_status);
634 new = drm_get_connector_status_name(connector->status);
635
636 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
637 "status updated from %s to %s\n",
638 connector->base.id,
639 connector->name,
640 old, new);
641
642 changed = true;
643 }
644 }
645 drm_connector_list_iter_end(&conn_iter);
646
647 mutex_unlock(&dev->mode_config.mutex);
648
649 out:
650 if (changed)
651 drm_kms_helper_hotplug_event(dev);
652
653 if (repoll)
654 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
655 }
656
657 /**
658 * drm_kms_helper_is_poll_worker - is %current task an output poll worker?
659 *
660 * Determine if %current task is an output poll worker. This can be used
661 * to select distinct code paths for output polling versus other contexts.
662 *
663 * One use case is to avoid a deadlock between the output poll worker and
664 * the autosuspend worker wherein the latter waits for polling to finish
665 * upon calling drm_kms_helper_poll_disable(), while the former waits for
666 * runtime suspend to finish upon calling pm_runtime_get_sync() in a
667 * connector ->detect hook.
668 */
drm_kms_helper_is_poll_worker(void)669 bool drm_kms_helper_is_poll_worker(void)
670 {
671 #ifndef __DragonFly__
672 struct work_struct *work = current_work();
673
674 return work && work->func == output_poll_execute;
675 #else
676 return false;
677 #endif
678 }
679 EXPORT_SYMBOL(drm_kms_helper_is_poll_worker);
680
681 /**
682 * drm_kms_helper_poll_disable - disable output polling
683 * @dev: drm_device
684 *
685 * This function disables the output polling work.
686 *
687 * Drivers can call this helper from their device suspend implementation. It is
688 * not an error to call this even when output polling isn't enabled or already
689 * disabled. Polling is re-enabled by calling drm_kms_helper_poll_enable().
690 *
691 * Note that calls to enable and disable polling must be strictly ordered, which
692 * is automatically the case when they're only call from suspend/resume
693 * callbacks.
694 */
drm_kms_helper_poll_disable(struct drm_device * dev)695 void drm_kms_helper_poll_disable(struct drm_device *dev)
696 {
697 if (!dev->mode_config.poll_enabled)
698 return;
699 cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
700 }
701 EXPORT_SYMBOL(drm_kms_helper_poll_disable);
702
703 /**
704 * drm_kms_helper_poll_init - initialize and enable output polling
705 * @dev: drm_device
706 *
707 * This function intializes and then also enables output polling support for
708 * @dev. Drivers which do not have reliable hotplug support in hardware can use
709 * this helper infrastructure to regularly poll such connectors for changes in
710 * their connection state.
711 *
712 * Drivers can control which connectors are polled by setting the
713 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
714 * connectors where probing live outputs can result in visual distortion drivers
715 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
716 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
717 * completely ignored by the polling logic.
718 *
719 * Note that a connector can be both polled and probed from the hotplug handler,
720 * in case the hotplug interrupt is known to be unreliable.
721 */
drm_kms_helper_poll_init(struct drm_device * dev)722 void drm_kms_helper_poll_init(struct drm_device *dev)
723 {
724 INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
725 dev->mode_config.poll_enabled = true;
726
727 drm_kms_helper_poll_enable(dev);
728 }
729 EXPORT_SYMBOL(drm_kms_helper_poll_init);
730
731 /**
732 * drm_kms_helper_poll_fini - disable output polling and clean it up
733 * @dev: drm_device
734 */
drm_kms_helper_poll_fini(struct drm_device * dev)735 void drm_kms_helper_poll_fini(struct drm_device *dev)
736 {
737 drm_kms_helper_poll_disable(dev);
738 }
739 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
740
741 /**
742 * drm_helper_hpd_irq_event - hotplug processing
743 * @dev: drm_device
744 *
745 * Drivers can use this helper function to run a detect cycle on all connectors
746 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
747 * other connectors are ignored, which is useful to avoid reprobing fixed
748 * panels.
749 *
750 * This helper function is useful for drivers which can't or don't track hotplug
751 * interrupts for each connector.
752 *
753 * Drivers which support hotplug interrupts for each connector individually and
754 * which have a more fine-grained detect logic should bypass this code and
755 * directly call drm_kms_helper_hotplug_event() in case the connector state
756 * changed.
757 *
758 * This function must be called from process context with no mode
759 * setting locks held.
760 *
761 * Note that a connector can be both polled and probed from the hotplug handler,
762 * in case the hotplug interrupt is known to be unreliable.
763 */
drm_helper_hpd_irq_event(struct drm_device * dev)764 bool drm_helper_hpd_irq_event(struct drm_device *dev)
765 {
766 struct drm_connector *connector;
767 struct drm_connector_list_iter conn_iter;
768 enum drm_connector_status old_status;
769 bool changed = false;
770
771 if (!dev->mode_config.poll_enabled)
772 return false;
773
774 mutex_lock(&dev->mode_config.mutex);
775 drm_connector_list_iter_begin(dev, &conn_iter);
776 drm_for_each_connector_iter(connector, &conn_iter) {
777 /* Only handle HPD capable connectors. */
778 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
779 continue;
780
781 old_status = connector->status;
782
783 connector->status = drm_helper_probe_detect(connector, NULL, false);
784 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
785 connector->base.id,
786 connector->name,
787 drm_get_connector_status_name(old_status),
788 drm_get_connector_status_name(connector->status));
789 if (old_status != connector->status)
790 changed = true;
791 }
792 drm_connector_list_iter_end(&conn_iter);
793 mutex_unlock(&dev->mode_config.mutex);
794
795 if (changed)
796 drm_kms_helper_hotplug_event(dev);
797
798 return changed;
799 }
800 EXPORT_SYMBOL(drm_helper_hpd_irq_event);
801