Line data Source code
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/drm_bridge.h>
36 : #include <drm/drm_client.h>
37 : #include <drm/drm_crtc.h>
38 : #include <drm/drm_edid.h>
39 : #include <drm/drm_fb_helper.h>
40 : #include <drm/drm_fourcc.h>
41 : #include <drm/drm_modeset_helper_vtables.h>
42 : #include <drm/drm_print.h>
43 : #include <drm/drm_probe_helper.h>
44 : #include <drm/drm_sysfs.h>
45 :
46 : #include "drm_crtc_helper_internal.h"
47 :
48 : /**
49 : * DOC: output probing helper overview
50 : *
51 : * This library provides some helper code for output probing. It provides an
52 : * implementation of the core &drm_connector_funcs.fill_modes interface with
53 : * drm_helper_probe_single_connector_modes().
54 : *
55 : * It also provides support for polling connectors with a work item and for
56 : * generic hotplug interrupt handling where the driver doesn't or cannot keep
57 : * track of a per-connector hpd interrupt.
58 : *
59 : * This helper library can be used independently of the modeset helper library.
60 : * Drivers can also overwrite different parts e.g. use their own hotplug
61 : * handling code to avoid probing unrelated outputs.
62 : *
63 : * The probe helpers share the function table structures with other display
64 : * helper libraries. See &struct drm_connector_helper_funcs for the details.
65 : */
66 :
67 : static bool drm_kms_helper_poll = true;
68 : module_param_named(poll, drm_kms_helper_poll, bool, 0600);
69 :
70 : static enum drm_mode_status
71 : drm_mode_validate_flag(const struct drm_display_mode *mode,
72 : int flags)
73 : {
74 0 : if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
75 0 : !(flags & DRM_MODE_FLAG_INTERLACE))
76 : return MODE_NO_INTERLACE;
77 :
78 0 : if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
79 0 : !(flags & DRM_MODE_FLAG_DBLSCAN))
80 : return MODE_NO_DBLESCAN;
81 :
82 0 : if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
83 0 : !(flags & DRM_MODE_FLAG_3D_MASK))
84 : return MODE_NO_STEREO;
85 :
86 : return MODE_OK;
87 : }
88 :
89 : static int
90 0 : drm_mode_validate_pipeline(struct drm_display_mode *mode,
91 : struct drm_connector *connector,
92 : struct drm_modeset_acquire_ctx *ctx,
93 : enum drm_mode_status *status)
94 : {
95 0 : struct drm_device *dev = connector->dev;
96 : struct drm_encoder *encoder;
97 : int ret;
98 :
99 : /* Step 1: Validate against connector */
100 0 : ret = drm_connector_mode_valid(connector, mode, ctx, status);
101 0 : if (ret || *status != MODE_OK)
102 : return ret;
103 :
104 : /* Step 2: Validate against encoders and crtcs */
105 0 : drm_connector_for_each_possible_encoder(connector, encoder) {
106 : struct drm_bridge *bridge;
107 : struct drm_crtc *crtc;
108 :
109 0 : *status = drm_encoder_mode_valid(encoder, mode);
110 0 : if (*status != MODE_OK) {
111 : /* No point in continuing for crtc check as this encoder
112 : * will not accept the mode anyway. If all encoders
113 : * reject the mode then, at exit, ret will not be
114 : * MODE_OK. */
115 0 : continue;
116 : }
117 :
118 0 : bridge = drm_bridge_chain_get_first_bridge(encoder);
119 0 : *status = drm_bridge_chain_mode_valid(bridge,
120 0 : &connector->display_info,
121 : mode);
122 0 : if (*status != MODE_OK) {
123 : /* There is also no point in continuing for crtc check
124 : * here. */
125 0 : continue;
126 : }
127 :
128 0 : drm_for_each_crtc(crtc, dev) {
129 0 : if (!drm_encoder_crtc_ok(encoder, crtc))
130 0 : continue;
131 :
132 0 : *status = drm_crtc_mode_valid(crtc, mode);
133 0 : if (*status == MODE_OK) {
134 : /* If we get to this point there is at least
135 : * one combination of encoder+crtc that works
136 : * for this mode. Lets return now. */
137 : return 0;
138 : }
139 : }
140 : }
141 :
142 : return 0;
143 : }
144 :
145 0 : static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
146 : {
147 : struct drm_cmdline_mode *cmdline_mode;
148 : struct drm_display_mode *mode;
149 :
150 0 : cmdline_mode = &connector->cmdline_mode;
151 0 : if (!cmdline_mode->specified)
152 : return 0;
153 :
154 : /* Only add a GTF mode if we find no matching probed modes */
155 0 : list_for_each_entry(mode, &connector->probed_modes, head) {
156 0 : if (mode->hdisplay != cmdline_mode->xres ||
157 0 : mode->vdisplay != cmdline_mode->yres)
158 0 : continue;
159 :
160 0 : if (cmdline_mode->refresh_specified) {
161 : /* The probed mode's vrefresh is set until later */
162 0 : if (drm_mode_vrefresh(mode) != cmdline_mode->refresh)
163 0 : continue;
164 : }
165 :
166 : /* Mark the matching mode as being preferred by the user */
167 0 : mode->type |= DRM_MODE_TYPE_USERDEF;
168 0 : return 0;
169 : }
170 :
171 0 : mode = drm_mode_create_from_cmdline_mode(connector->dev,
172 : cmdline_mode);
173 0 : if (mode == NULL)
174 : return 0;
175 :
176 0 : drm_mode_probed_add(connector, mode);
177 0 : return 1;
178 : }
179 :
180 0 : enum drm_mode_status drm_crtc_mode_valid(struct drm_crtc *crtc,
181 : const struct drm_display_mode *mode)
182 : {
183 0 : const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
184 :
185 0 : if (!crtc_funcs || !crtc_funcs->mode_valid)
186 : return MODE_OK;
187 :
188 0 : return crtc_funcs->mode_valid(crtc, mode);
189 : }
190 :
191 0 : enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder,
192 : const struct drm_display_mode *mode)
193 : {
194 0 : const struct drm_encoder_helper_funcs *encoder_funcs =
195 : encoder->helper_private;
196 :
197 0 : if (!encoder_funcs || !encoder_funcs->mode_valid)
198 : return MODE_OK;
199 :
200 0 : return encoder_funcs->mode_valid(encoder, mode);
201 : }
202 :
203 : int
204 0 : drm_connector_mode_valid(struct drm_connector *connector,
205 : struct drm_display_mode *mode,
206 : struct drm_modeset_acquire_ctx *ctx,
207 : enum drm_mode_status *status)
208 : {
209 0 : const struct drm_connector_helper_funcs *connector_funcs =
210 : connector->helper_private;
211 0 : int ret = 0;
212 :
213 0 : if (!connector_funcs)
214 0 : *status = MODE_OK;
215 0 : else if (connector_funcs->mode_valid_ctx)
216 0 : ret = connector_funcs->mode_valid_ctx(connector, mode, ctx,
217 : status);
218 0 : else if (connector_funcs->mode_valid)
219 0 : *status = connector_funcs->mode_valid(connector, mode);
220 : else
221 0 : *status = MODE_OK;
222 :
223 0 : return ret;
224 : }
225 :
226 : #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
227 : /**
228 : * drm_kms_helper_poll_enable - re-enable output polling.
229 : * @dev: drm_device
230 : *
231 : * This function re-enables the output polling work, after it has been
232 : * temporarily disabled using drm_kms_helper_poll_disable(), for example over
233 : * suspend/resume.
234 : *
235 : * Drivers can call this helper from their device resume implementation. It is
236 : * not an error to call this even when output polling isn't enabled.
237 : *
238 : * Note that calls to enable and disable polling must be strictly ordered, which
239 : * is automatically the case when they're only call from suspend/resume
240 : * callbacks.
241 : */
242 0 : void drm_kms_helper_poll_enable(struct drm_device *dev)
243 : {
244 0 : bool poll = false;
245 : struct drm_connector *connector;
246 : struct drm_connector_list_iter conn_iter;
247 0 : unsigned long delay = DRM_OUTPUT_POLL_PERIOD;
248 :
249 0 : if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
250 0 : return;
251 :
252 0 : drm_connector_list_iter_begin(dev, &conn_iter);
253 0 : drm_for_each_connector_iter(connector, &conn_iter) {
254 0 : if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
255 : DRM_CONNECTOR_POLL_DISCONNECT))
256 0 : poll = true;
257 : }
258 0 : drm_connector_list_iter_end(&conn_iter);
259 :
260 0 : if (dev->mode_config.delayed_event) {
261 : /*
262 : * FIXME:
263 : *
264 : * Use short (1s) delay to handle the initial delayed event.
265 : * This delay should not be needed, but Optimus/nouveau will
266 : * fail in a mysterious way if the delayed event is handled as
267 : * soon as possible like it is done in
268 : * drm_helper_probe_single_connector_modes() in case the poll
269 : * was enabled before.
270 : */
271 0 : poll = true;
272 0 : delay = HZ;
273 : }
274 :
275 0 : if (poll)
276 0 : schedule_delayed_work(&dev->mode_config.output_poll_work, delay);
277 : }
278 : EXPORT_SYMBOL(drm_kms_helper_poll_enable);
279 :
280 : static enum drm_connector_status
281 0 : drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force)
282 : {
283 0 : const struct drm_connector_helper_funcs *funcs = connector->helper_private;
284 : struct drm_modeset_acquire_ctx ctx;
285 : int ret;
286 :
287 0 : drm_modeset_acquire_init(&ctx, 0);
288 :
289 : retry:
290 0 : ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, &ctx);
291 0 : if (!ret) {
292 0 : if (funcs->detect_ctx)
293 0 : ret = funcs->detect_ctx(connector, &ctx, force);
294 0 : else if (connector->funcs->detect)
295 0 : ret = connector->funcs->detect(connector, force);
296 : else
297 : ret = connector_status_connected;
298 : }
299 :
300 0 : if (ret == -EDEADLK) {
301 0 : drm_modeset_backoff(&ctx);
302 0 : goto retry;
303 : }
304 :
305 0 : if (WARN_ON(ret < 0))
306 0 : ret = connector_status_unknown;
307 :
308 0 : if (ret != connector->status)
309 0 : connector->epoch_counter += 1;
310 :
311 0 : drm_modeset_drop_locks(&ctx);
312 0 : drm_modeset_acquire_fini(&ctx);
313 :
314 0 : return ret;
315 : }
316 :
317 : /**
318 : * drm_helper_probe_detect - probe connector status
319 : * @connector: connector to probe
320 : * @ctx: acquire_ctx, or NULL to let this function handle locking.
321 : * @force: Whether destructive probe operations should be performed.
322 : *
323 : * This function calls the detect callbacks of the connector.
324 : * This function returns &drm_connector_status, or
325 : * if @ctx is set, it might also return -EDEADLK.
326 : */
327 : int
328 0 : drm_helper_probe_detect(struct drm_connector *connector,
329 : struct drm_modeset_acquire_ctx *ctx,
330 : bool force)
331 : {
332 0 : const struct drm_connector_helper_funcs *funcs = connector->helper_private;
333 0 : struct drm_device *dev = connector->dev;
334 : int ret;
335 :
336 0 : if (!ctx)
337 0 : return drm_helper_probe_detect_ctx(connector, force);
338 :
339 0 : ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
340 0 : if (ret)
341 : return ret;
342 :
343 0 : if (funcs->detect_ctx)
344 0 : ret = funcs->detect_ctx(connector, ctx, force);
345 0 : else if (connector->funcs->detect)
346 0 : ret = connector->funcs->detect(connector, force);
347 : else
348 : ret = connector_status_connected;
349 :
350 0 : if (ret != connector->status)
351 0 : connector->epoch_counter += 1;
352 :
353 : return ret;
354 : }
355 : EXPORT_SYMBOL(drm_helper_probe_detect);
356 :
357 : /**
358 : * drm_helper_probe_single_connector_modes - get complete set of display modes
359 : * @connector: connector to probe
360 : * @maxX: max width for modes
361 : * @maxY: max height for modes
362 : *
363 : * Based on the helper callbacks implemented by @connector in struct
364 : * &drm_connector_helper_funcs try to detect all valid modes. Modes will first
365 : * be added to the connector's probed_modes list, then culled (based on validity
366 : * and the @maxX, @maxY parameters) and put into the normal modes list.
367 : *
368 : * Intended to be used as a generic implementation of the
369 : * &drm_connector_funcs.fill_modes() vfunc for drivers that use the CRTC helpers
370 : * for output mode filtering and detection.
371 : *
372 : * The basic procedure is as follows
373 : *
374 : * 1. All modes currently on the connector's modes list are marked as stale
375 : *
376 : * 2. New modes are added to the connector's probed_modes list with
377 : * drm_mode_probed_add(). New modes start their life with status as OK.
378 : * Modes are added from a single source using the following priority order.
379 : *
380 : * - &drm_connector_helper_funcs.get_modes vfunc
381 : * - if the connector status is connector_status_connected, standard
382 : * VESA DMT modes up to 1024x768 are automatically added
383 : * (drm_add_modes_noedid())
384 : *
385 : * Finally modes specified via the kernel command line (video=...) are
386 : * added in addition to what the earlier probes produced
387 : * (drm_helper_probe_add_cmdline_mode()). These modes are generated
388 : * using the VESA GTF/CVT formulas.
389 : *
390 : * 3. Modes are moved from the probed_modes list to the modes list. Potential
391 : * duplicates are merged together (see drm_connector_list_update()).
392 : * After this step the probed_modes list will be empty again.
393 : *
394 : * 4. Any non-stale mode on the modes list then undergoes validation
395 : *
396 : * - drm_mode_validate_basic() performs basic sanity checks
397 : * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
398 : * (if specified)
399 : * - drm_mode_validate_flag() checks the modes against basic connector
400 : * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed)
401 : * - the optional &drm_connector_helper_funcs.mode_valid or
402 : * &drm_connector_helper_funcs.mode_valid_ctx helpers can perform driver
403 : * and/or sink specific checks
404 : * - the optional &drm_crtc_helper_funcs.mode_valid,
405 : * &drm_bridge_funcs.mode_valid and &drm_encoder_helper_funcs.mode_valid
406 : * helpers can perform driver and/or source specific checks which are also
407 : * enforced by the modeset/atomic helpers
408 : *
409 : * 5. Any mode whose status is not OK is pruned from the connector's modes list,
410 : * accompanied by a debug message indicating the reason for the mode's
411 : * rejection (see drm_mode_prune_invalid()).
412 : *
413 : * Returns:
414 : * The number of modes found on @connector.
415 : */
416 0 : int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
417 : uint32_t maxX, uint32_t maxY)
418 : {
419 0 : struct drm_device *dev = connector->dev;
420 : struct drm_display_mode *mode;
421 0 : const struct drm_connector_helper_funcs *connector_funcs =
422 : connector->helper_private;
423 0 : int count = 0, ret;
424 0 : int mode_flags = 0;
425 0 : bool verbose_prune = true;
426 : enum drm_connector_status old_status;
427 : struct drm_modeset_acquire_ctx ctx;
428 :
429 0 : WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
430 :
431 0 : drm_modeset_acquire_init(&ctx, 0);
432 :
433 0 : DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
434 : connector->name);
435 :
436 : retry:
437 0 : ret = drm_modeset_lock(&dev->mode_config.connection_mutex, &ctx);
438 0 : if (ret == -EDEADLK) {
439 0 : drm_modeset_backoff(&ctx);
440 0 : goto retry;
441 : } else
442 0 : WARN_ON(ret < 0);
443 :
444 : /* set all old modes to the stale state */
445 0 : list_for_each_entry(mode, &connector->modes, head)
446 0 : mode->status = MODE_STALE;
447 :
448 0 : old_status = connector->status;
449 :
450 0 : if (connector->force) {
451 0 : if (connector->force == DRM_FORCE_ON ||
452 : connector->force == DRM_FORCE_ON_DIGITAL)
453 0 : connector->status = connector_status_connected;
454 : else
455 0 : connector->status = connector_status_disconnected;
456 0 : if (connector->funcs->force)
457 0 : connector->funcs->force(connector);
458 : } else {
459 0 : ret = drm_helper_probe_detect(connector, &ctx, true);
460 :
461 0 : if (ret == -EDEADLK) {
462 0 : drm_modeset_backoff(&ctx);
463 0 : goto retry;
464 0 : } else if (WARN(ret < 0, "Invalid return value %i for connector detection\n", ret))
465 0 : ret = connector_status_unknown;
466 :
467 0 : connector->status = ret;
468 : }
469 :
470 : /*
471 : * Normally either the driver's hpd code or the poll loop should
472 : * pick up any changes and fire the hotplug event. But if
473 : * userspace sneaks in a probe, we might miss a change. Hence
474 : * check here, and if anything changed start the hotplug code.
475 : */
476 0 : if (old_status != connector->status) {
477 0 : DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
478 : connector->base.id,
479 : connector->name,
480 : drm_get_connector_status_name(old_status),
481 : drm_get_connector_status_name(connector->status));
482 :
483 : /*
484 : * The hotplug event code might call into the fb
485 : * helpers, and so expects that we do not hold any
486 : * locks. Fire up the poll struct instead, it will
487 : * disable itself again.
488 : */
489 0 : dev->mode_config.delayed_event = true;
490 0 : if (dev->mode_config.poll_enabled)
491 0 : schedule_delayed_work(&dev->mode_config.output_poll_work,
492 : 0);
493 : }
494 :
495 : /* Re-enable polling in case the global poll config changed. */
496 0 : if (drm_kms_helper_poll != dev->mode_config.poll_running)
497 0 : drm_kms_helper_poll_enable(dev);
498 :
499 0 : dev->mode_config.poll_running = drm_kms_helper_poll;
500 :
501 0 : if (connector->status == connector_status_disconnected) {
502 0 : DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
503 : connector->base.id, connector->name);
504 0 : drm_connector_update_edid_property(connector, NULL);
505 0 : verbose_prune = false;
506 0 : goto prune;
507 : }
508 :
509 0 : count = (*connector_funcs->get_modes)(connector);
510 :
511 : /*
512 : * Fallback for when DDC probe failed in drm_get_edid() and thus skipped
513 : * override/firmware EDID.
514 : */
515 0 : if (count == 0 && connector->status == connector_status_connected)
516 0 : count = drm_add_override_edid_modes(connector);
517 :
518 0 : if (count == 0 && (connector->status == connector_status_connected ||
519 : connector->status == connector_status_unknown))
520 0 : count = drm_add_modes_noedid(connector, 1024, 768);
521 0 : count += drm_helper_probe_add_cmdline_mode(connector);
522 0 : if (count == 0)
523 : goto prune;
524 :
525 0 : drm_connector_list_update(connector);
526 :
527 0 : if (connector->interlace_allowed)
528 0 : mode_flags |= DRM_MODE_FLAG_INTERLACE;
529 0 : if (connector->doublescan_allowed)
530 0 : mode_flags |= DRM_MODE_FLAG_DBLSCAN;
531 0 : if (connector->stereo_allowed)
532 0 : mode_flags |= DRM_MODE_FLAG_3D_MASK;
533 :
534 0 : list_for_each_entry(mode, &connector->modes, head) {
535 0 : if (mode->status != MODE_OK)
536 0 : continue;
537 :
538 0 : mode->status = drm_mode_validate_driver(dev, mode);
539 0 : if (mode->status != MODE_OK)
540 0 : continue;
541 :
542 0 : mode->status = drm_mode_validate_size(mode, maxX, maxY);
543 0 : if (mode->status != MODE_OK)
544 0 : continue;
545 :
546 0 : mode->status = drm_mode_validate_flag(mode, mode_flags);
547 0 : if (mode->status != MODE_OK)
548 0 : continue;
549 :
550 0 : ret = drm_mode_validate_pipeline(mode, connector, &ctx,
551 : &mode->status);
552 0 : if (ret) {
553 0 : drm_dbg_kms(dev,
554 : "drm_mode_validate_pipeline failed: %d\n",
555 : ret);
556 :
557 0 : if (drm_WARN_ON_ONCE(dev, ret != -EDEADLK)) {
558 0 : mode->status = MODE_ERROR;
559 : } else {
560 0 : drm_modeset_backoff(&ctx);
561 0 : goto retry;
562 : }
563 : }
564 :
565 0 : if (mode->status != MODE_OK)
566 0 : continue;
567 0 : mode->status = drm_mode_validate_ycbcr420(mode, connector);
568 : }
569 :
570 : prune:
571 0 : drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
572 :
573 0 : drm_modeset_drop_locks(&ctx);
574 0 : drm_modeset_acquire_fini(&ctx);
575 :
576 0 : if (list_empty(&connector->modes))
577 : return 0;
578 :
579 0 : drm_mode_sort(&connector->modes);
580 :
581 0 : DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
582 : connector->name);
583 0 : list_for_each_entry(mode, &connector->modes, head) {
584 0 : drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
585 0 : drm_mode_debug_printmodeline(mode);
586 : }
587 :
588 : return count;
589 : }
590 : EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
591 :
592 : /**
593 : * drm_kms_helper_hotplug_event - fire off KMS hotplug events
594 : * @dev: drm_device whose connector state changed
595 : *
596 : * This function fires off the uevent for userspace and also calls the
597 : * output_poll_changed function, which is most commonly used to inform the fbdev
598 : * emulation code and allow it to update the fbcon output configuration.
599 : *
600 : * Drivers should call this from their hotplug handling code when a change is
601 : * detected. Note that this function does not do any output detection of its
602 : * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
603 : * driver already.
604 : *
605 : * This function must be called from process context with no mode
606 : * setting locks held.
607 : *
608 : * If only a single connector has changed, consider calling
609 : * drm_kms_helper_connector_hotplug_event() instead.
610 : */
611 0 : void drm_kms_helper_hotplug_event(struct drm_device *dev)
612 : {
613 : /* send a uevent + call fbdev */
614 0 : drm_sysfs_hotplug_event(dev);
615 0 : if (dev->mode_config.funcs->output_poll_changed)
616 0 : dev->mode_config.funcs->output_poll_changed(dev);
617 :
618 0 : drm_client_dev_hotplug(dev);
619 0 : }
620 : EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
621 :
622 : /**
623 : * drm_kms_helper_connector_hotplug_event - fire off a KMS connector hotplug event
624 : * @connector: drm_connector which has changed
625 : *
626 : * This is the same as drm_kms_helper_hotplug_event(), except it fires a more
627 : * fine-grained uevent for a single connector.
628 : */
629 0 : void drm_kms_helper_connector_hotplug_event(struct drm_connector *connector)
630 : {
631 0 : struct drm_device *dev = connector->dev;
632 :
633 : /* send a uevent + call fbdev */
634 0 : drm_sysfs_connector_hotplug_event(connector);
635 0 : if (dev->mode_config.funcs->output_poll_changed)
636 0 : dev->mode_config.funcs->output_poll_changed(dev);
637 :
638 0 : drm_client_dev_hotplug(dev);
639 0 : }
640 : EXPORT_SYMBOL(drm_kms_helper_connector_hotplug_event);
641 :
642 0 : static void output_poll_execute(struct work_struct *work)
643 : {
644 0 : struct delayed_work *delayed_work = to_delayed_work(work);
645 0 : struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
646 : struct drm_connector *connector;
647 : struct drm_connector_list_iter conn_iter;
648 : enum drm_connector_status old_status;
649 0 : bool repoll = false, changed;
650 : u64 old_epoch_counter;
651 :
652 0 : if (!dev->mode_config.poll_enabled)
653 0 : return;
654 :
655 : /* Pick up any changes detected by the probe functions. */
656 0 : changed = dev->mode_config.delayed_event;
657 0 : dev->mode_config.delayed_event = false;
658 :
659 0 : if (!drm_kms_helper_poll)
660 : goto out;
661 :
662 0 : if (!mutex_trylock(&dev->mode_config.mutex)) {
663 : repoll = true;
664 : goto out;
665 : }
666 :
667 0 : drm_connector_list_iter_begin(dev, &conn_iter);
668 0 : drm_for_each_connector_iter(connector, &conn_iter) {
669 : /* Ignore forced connectors. */
670 0 : if (connector->force)
671 0 : continue;
672 :
673 : /* Ignore HPD capable connectors and connectors where we don't
674 : * want any hotplug detection at all for polling. */
675 0 : if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
676 0 : continue;
677 :
678 0 : old_status = connector->status;
679 : /* if we are connected and don't want to poll for disconnect
680 : skip it */
681 0 : if (old_status == connector_status_connected &&
682 : !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
683 0 : continue;
684 :
685 0 : repoll = true;
686 :
687 0 : old_epoch_counter = connector->epoch_counter;
688 0 : connector->status = drm_helper_probe_detect(connector, NULL, false);
689 0 : if (old_epoch_counter != connector->epoch_counter) {
690 : const char *old, *new;
691 :
692 : /*
693 : * The poll work sets force=false when calling detect so
694 : * that drivers can avoid to do disruptive tests (e.g.
695 : * when load detect cycles could cause flickering on
696 : * other, running displays). This bears the risk that we
697 : * flip-flop between unknown here in the poll work and
698 : * the real state when userspace forces a full detect
699 : * call after receiving a hotplug event due to this
700 : * change.
701 : *
702 : * Hence clamp an unknown detect status to the old
703 : * value.
704 : */
705 0 : if (connector->status == connector_status_unknown) {
706 0 : connector->status = old_status;
707 0 : continue;
708 : }
709 :
710 0 : old = drm_get_connector_status_name(old_status);
711 0 : new = drm_get_connector_status_name(connector->status);
712 :
713 0 : DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
714 : "status updated from %s to %s\n",
715 : connector->base.id,
716 : connector->name,
717 : old, new);
718 0 : DRM_DEBUG_KMS("[CONNECTOR:%d:%s] epoch counter %llu -> %llu\n",
719 : connector->base.id, connector->name,
720 : old_epoch_counter, connector->epoch_counter);
721 :
722 0 : changed = true;
723 : }
724 : }
725 0 : drm_connector_list_iter_end(&conn_iter);
726 :
727 0 : mutex_unlock(&dev->mode_config.mutex);
728 :
729 : out:
730 0 : if (changed)
731 0 : drm_kms_helper_hotplug_event(dev);
732 :
733 0 : if (repoll)
734 : schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
735 : }
736 :
737 : /**
738 : * drm_kms_helper_is_poll_worker - is %current task an output poll worker?
739 : *
740 : * Determine if %current task is an output poll worker. This can be used
741 : * to select distinct code paths for output polling versus other contexts.
742 : *
743 : * One use case is to avoid a deadlock between the output poll worker and
744 : * the autosuspend worker wherein the latter waits for polling to finish
745 : * upon calling drm_kms_helper_poll_disable(), while the former waits for
746 : * runtime suspend to finish upon calling pm_runtime_get_sync() in a
747 : * connector ->detect hook.
748 : */
749 0 : bool drm_kms_helper_is_poll_worker(void)
750 : {
751 0 : struct work_struct *work = current_work();
752 :
753 0 : return work && work->func == output_poll_execute;
754 : }
755 : EXPORT_SYMBOL(drm_kms_helper_is_poll_worker);
756 :
757 : /**
758 : * drm_kms_helper_poll_disable - disable output polling
759 : * @dev: drm_device
760 : *
761 : * This function disables the output polling work.
762 : *
763 : * Drivers can call this helper from their device suspend implementation. It is
764 : * not an error to call this even when output polling isn't enabled or already
765 : * disabled. Polling is re-enabled by calling drm_kms_helper_poll_enable().
766 : *
767 : * Note that calls to enable and disable polling must be strictly ordered, which
768 : * is automatically the case when they're only call from suspend/resume
769 : * callbacks.
770 : */
771 0 : void drm_kms_helper_poll_disable(struct drm_device *dev)
772 : {
773 0 : if (!dev->mode_config.poll_enabled)
774 : return;
775 0 : cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
776 : }
777 : EXPORT_SYMBOL(drm_kms_helper_poll_disable);
778 :
779 : /**
780 : * drm_kms_helper_poll_init - initialize and enable output polling
781 : * @dev: drm_device
782 : *
783 : * This function initializes and then also enables output polling support for
784 : * @dev. Drivers which do not have reliable hotplug support in hardware can use
785 : * this helper infrastructure to regularly poll such connectors for changes in
786 : * their connection state.
787 : *
788 : * Drivers can control which connectors are polled by setting the
789 : * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
790 : * connectors where probing live outputs can result in visual distortion drivers
791 : * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
792 : * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
793 : * completely ignored by the polling logic.
794 : *
795 : * Note that a connector can be both polled and probed from the hotplug handler,
796 : * in case the hotplug interrupt is known to be unreliable.
797 : */
798 0 : void drm_kms_helper_poll_init(struct drm_device *dev)
799 : {
800 0 : INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
801 0 : dev->mode_config.poll_enabled = true;
802 :
803 0 : drm_kms_helper_poll_enable(dev);
804 0 : }
805 : EXPORT_SYMBOL(drm_kms_helper_poll_init);
806 :
807 : /**
808 : * drm_kms_helper_poll_fini - disable output polling and clean it up
809 : * @dev: drm_device
810 : */
811 0 : void drm_kms_helper_poll_fini(struct drm_device *dev)
812 : {
813 0 : if (!dev->mode_config.poll_enabled)
814 : return;
815 :
816 0 : dev->mode_config.poll_enabled = false;
817 0 : cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
818 : }
819 : EXPORT_SYMBOL(drm_kms_helper_poll_fini);
820 :
821 0 : static bool check_connector_changed(struct drm_connector *connector)
822 : {
823 0 : struct drm_device *dev = connector->dev;
824 : enum drm_connector_status old_status;
825 : u64 old_epoch_counter;
826 :
827 : /* Only handle HPD capable connectors. */
828 0 : drm_WARN_ON(dev, !(connector->polled & DRM_CONNECTOR_POLL_HPD));
829 :
830 0 : drm_WARN_ON(dev, !mutex_is_locked(&dev->mode_config.mutex));
831 :
832 0 : old_status = connector->status;
833 0 : old_epoch_counter = connector->epoch_counter;
834 0 : connector->status = drm_helper_probe_detect(connector, NULL, false);
835 :
836 0 : if (old_epoch_counter == connector->epoch_counter) {
837 0 : drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Same epoch counter %llu\n",
838 : connector->base.id,
839 : connector->name,
840 : connector->epoch_counter);
841 :
842 0 : return false;
843 : }
844 :
845 0 : drm_dbg_kms(dev, "[CONNECTOR:%d:%s] status updated from %s to %s\n",
846 : connector->base.id,
847 : connector->name,
848 : drm_get_connector_status_name(old_status),
849 : drm_get_connector_status_name(connector->status));
850 :
851 0 : drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Changed epoch counter %llu => %llu\n",
852 : connector->base.id,
853 : connector->name,
854 : old_epoch_counter,
855 : connector->epoch_counter);
856 :
857 0 : return true;
858 : }
859 :
860 : /**
861 : * drm_connector_helper_hpd_irq_event - hotplug processing
862 : * @connector: drm_connector
863 : *
864 : * Drivers can use this helper function to run a detect cycle on a connector
865 : * which has the DRM_CONNECTOR_POLL_HPD flag set in its &polled member.
866 : *
867 : * This helper function is useful for drivers which can track hotplug
868 : * interrupts for a single connector. Drivers that want to send a
869 : * hotplug event for all connectors or can't track hotplug interrupts
870 : * per connector need to use drm_helper_hpd_irq_event().
871 : *
872 : * This function must be called from process context with no mode
873 : * setting locks held.
874 : *
875 : * Note that a connector can be both polled and probed from the hotplug
876 : * handler, in case the hotplug interrupt is known to be unreliable.
877 : *
878 : * Returns:
879 : * A boolean indicating whether the connector status changed or not
880 : */
881 0 : bool drm_connector_helper_hpd_irq_event(struct drm_connector *connector)
882 : {
883 0 : struct drm_device *dev = connector->dev;
884 : bool changed;
885 :
886 0 : mutex_lock(&dev->mode_config.mutex);
887 0 : changed = check_connector_changed(connector);
888 0 : mutex_unlock(&dev->mode_config.mutex);
889 :
890 0 : if (changed) {
891 0 : drm_kms_helper_connector_hotplug_event(connector);
892 0 : drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Sent hotplug event\n",
893 : connector->base.id,
894 : connector->name);
895 : }
896 :
897 0 : return changed;
898 : }
899 : EXPORT_SYMBOL(drm_connector_helper_hpd_irq_event);
900 :
901 : /**
902 : * drm_helper_hpd_irq_event - hotplug processing
903 : * @dev: drm_device
904 : *
905 : * Drivers can use this helper function to run a detect cycle on all connectors
906 : * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
907 : * other connectors are ignored, which is useful to avoid reprobing fixed
908 : * panels.
909 : *
910 : * This helper function is useful for drivers which can't or don't track hotplug
911 : * interrupts for each connector.
912 : *
913 : * Drivers which support hotplug interrupts for each connector individually and
914 : * which have a more fine-grained detect logic can use
915 : * drm_connector_helper_hpd_irq_event(). Alternatively, they should bypass this
916 : * code and directly call drm_kms_helper_hotplug_event() in case the connector
917 : * state changed.
918 : *
919 : * This function must be called from process context with no mode
920 : * setting locks held.
921 : *
922 : * Note that a connector can be both polled and probed from the hotplug handler,
923 : * in case the hotplug interrupt is known to be unreliable.
924 : *
925 : * Returns:
926 : * A boolean indicating whether the connector status changed or not
927 : */
928 0 : bool drm_helper_hpd_irq_event(struct drm_device *dev)
929 : {
930 0 : struct drm_connector *connector, *first_changed_connector = NULL;
931 : struct drm_connector_list_iter conn_iter;
932 0 : int changed = 0;
933 :
934 0 : if (!dev->mode_config.poll_enabled)
935 : return false;
936 :
937 0 : mutex_lock(&dev->mode_config.mutex);
938 0 : drm_connector_list_iter_begin(dev, &conn_iter);
939 0 : drm_for_each_connector_iter(connector, &conn_iter) {
940 : /* Only handle HPD capable connectors. */
941 0 : if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
942 0 : continue;
943 :
944 0 : if (check_connector_changed(connector)) {
945 0 : if (!first_changed_connector) {
946 0 : drm_connector_get(connector);
947 0 : first_changed_connector = connector;
948 : }
949 :
950 0 : changed++;
951 : }
952 : }
953 0 : drm_connector_list_iter_end(&conn_iter);
954 0 : mutex_unlock(&dev->mode_config.mutex);
955 :
956 0 : if (changed == 1)
957 0 : drm_kms_helper_connector_hotplug_event(first_changed_connector);
958 0 : else if (changed > 0)
959 0 : drm_kms_helper_hotplug_event(dev);
960 :
961 0 : if (first_changed_connector)
962 : drm_connector_put(first_changed_connector);
963 :
964 0 : return changed;
965 : }
966 : EXPORT_SYMBOL(drm_helper_hpd_irq_event);
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