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1/*
2 * Copyright © 2015 Intel Corporation
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, sublicense,
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 next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * 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 NONINFRINGEMENT. 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 DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24#include <linux/kernel.h>
25
26#include <drm/i915_drm.h>
27
28#include "i915_drv.h"
29#include "intel_display_types.h"
30#include "intel_hotplug.h"
31
32/**
33 * DOC: Hotplug
34 *
35 * Simply put, hotplug occurs when a display is connected to or disconnected
36 * from the system. However, there may be adapters and docking stations and
37 * Display Port short pulses and MST devices involved, complicating matters.
38 *
39 * Hotplug in i915 is handled in many different levels of abstraction.
40 *
41 * The platform dependent interrupt handling code in i915_irq.c enables,
42 * disables, and does preliminary handling of the interrupts. The interrupt
43 * handlers gather the hotplug detect (HPD) information from relevant registers
44 * into a platform independent mask of hotplug pins that have fired.
45 *
46 * The platform independent interrupt handler intel_hpd_irq_handler() in
47 * intel_hotplug.c does hotplug irq storm detection and mitigation, and passes
48 * further processing to appropriate bottom halves (Display Port specific and
49 * regular hotplug).
50 *
51 * The Display Port work function i915_digport_work_func() calls into
52 * intel_dp_hpd_pulse() via hooks, which handles DP short pulses and DP MST long
53 * pulses, with failures and non-MST long pulses triggering regular hotplug
54 * processing on the connector.
55 *
56 * The regular hotplug work function i915_hotplug_work_func() calls connector
57 * detect hooks, and, if connector status changes, triggers sending of hotplug
58 * uevent to userspace via drm_kms_helper_hotplug_event().
59 *
60 * Finally, the userspace is responsible for triggering a modeset upon receiving
61 * the hotplug uevent, disabling or enabling the crtc as needed.
62 *
63 * The hotplug interrupt storm detection and mitigation code keeps track of the
64 * number of interrupts per hotplug pin per a period of time, and if the number
65 * of interrupts exceeds a certain threshold, the interrupt is disabled for a
66 * while before being re-enabled. The intention is to mitigate issues raising
67 * from broken hardware triggering massive amounts of interrupts and grinding
68 * the system to a halt.
69 *
70 * Current implementation expects that hotplug interrupt storm will not be
71 * seen when display port sink is connected, hence on platforms whose DP
72 * callback is handled by i915_digport_work_func reenabling of hpd is not
73 * performed (it was never expected to be disabled in the first place ;) )
74 * this is specific to DP sinks handled by this routine and any other display
75 * such as HDMI or DVI enabled on the same port will have proper logic since
76 * it will use i915_hotplug_work_func where this logic is handled.
77 */
78
79/**
80 * intel_hpd_pin_default - return default pin associated with certain port.
81 * @dev_priv: private driver data pointer
82 * @port: the hpd port to get associated pin
83 *
84 * It is only valid and used by digital port encoder.
85 *
86 * Return pin that is associatade with @port and HDP_NONE if no pin is
87 * hard associated with that @port.
88 */
89enum hpd_pin intel_hpd_pin_default(struct drm_i915_private *dev_priv,
90 enum port port)
91{
92 switch (port) {
93 case PORT_A:
94 return HPD_PORT_A;
95 case PORT_B:
96 return HPD_PORT_B;
97 case PORT_C:
98 return HPD_PORT_C;
99 case PORT_D:
100 return HPD_PORT_D;
101 case PORT_E:
102 return HPD_PORT_E;
103 case PORT_F:
104 if (IS_CNL_WITH_PORT_F(dev_priv))
105 return HPD_PORT_E;
106 return HPD_PORT_F;
107 case PORT_G:
108 return HPD_PORT_G;
109 case PORT_H:
110 return HPD_PORT_H;
111 case PORT_I:
112 return HPD_PORT_I;
113 default:
114 MISSING_CASE(port);
115 return HPD_NONE;
116 }
117}
118
119#define HPD_STORM_DETECT_PERIOD 1000
120#define HPD_STORM_REENABLE_DELAY (2 * 60 * 1000)
121#define HPD_RETRY_DELAY 1000
122
123/**
124 * intel_hpd_irq_storm_detect - gather stats and detect HPD IRQ storm on a pin
125 * @dev_priv: private driver data pointer
126 * @pin: the pin to gather stats on
127 * @long_hpd: whether the HPD IRQ was long or short
128 *
129 * Gather stats about HPD IRQs from the specified @pin, and detect IRQ
130 * storms. Only the pin specific stats and state are changed, the caller is
131 * responsible for further action.
132 *
133 * The number of IRQs that are allowed within @HPD_STORM_DETECT_PERIOD is
134 * stored in @dev_priv->hotplug.hpd_storm_threshold which defaults to
135 * @HPD_STORM_DEFAULT_THRESHOLD. Long IRQs count as +10 to this threshold, and
136 * short IRQs count as +1. If this threshold is exceeded, it's considered an
137 * IRQ storm and the IRQ state is set to @HPD_MARK_DISABLED.
138 *
139 * By default, most systems will only count long IRQs towards
140 * &dev_priv->hotplug.hpd_storm_threshold. However, some older systems also
141 * suffer from short IRQ storms and must also track these. Because short IRQ
142 * storms are naturally caused by sideband interactions with DP MST devices,
143 * short IRQ detection is only enabled for systems without DP MST support.
144 * Systems which are new enough to support DP MST are far less likely to
145 * suffer from IRQ storms at all, so this is fine.
146 *
147 * The HPD threshold can be controlled through i915_hpd_storm_ctl in debugfs,
148 * and should only be adjusted for automated hotplug testing.
149 *
150 * Return true if an IRQ storm was detected on @pin.
151 */
152static bool intel_hpd_irq_storm_detect(struct drm_i915_private *dev_priv,
153 enum hpd_pin pin, bool long_hpd)
154{
155 struct i915_hotplug *hpd = &dev_priv->hotplug;
156 unsigned long start = hpd->stats[pin].last_jiffies;
157 unsigned long end = start + msecs_to_jiffies(HPD_STORM_DETECT_PERIOD);
158 const int increment = long_hpd ? 10 : 1;
159 const int threshold = hpd->hpd_storm_threshold;
160 bool storm = false;
161
162 if (!threshold ||
163 (!long_hpd && !dev_priv->hotplug.hpd_short_storm_enabled))
164 return false;
165
166 if (!time_in_range(jiffies, start, end)) {
167 hpd->stats[pin].last_jiffies = jiffies;
168 hpd->stats[pin].count = 0;
169 }
170
171 hpd->stats[pin].count += increment;
172 if (hpd->stats[pin].count > threshold) {
173 hpd->stats[pin].state = HPD_MARK_DISABLED;
174 DRM_DEBUG_KMS("HPD interrupt storm detected on PIN %d\n", pin);
175 storm = true;
176 } else {
177 DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: %d\n", pin,
178 hpd->stats[pin].count);
179 }
180
181 return storm;
182}
183
184static void
185intel_hpd_irq_storm_switch_to_polling(struct drm_i915_private *dev_priv)
186{
187 struct drm_device *dev = &dev_priv->drm;
188 struct intel_connector *intel_connector;
189 struct intel_encoder *intel_encoder;
190 struct drm_connector *connector;
191 struct drm_connector_list_iter conn_iter;
192 enum hpd_pin pin;
193 bool hpd_disabled = false;
194
195 lockdep_assert_held(&dev_priv->irq_lock);
196
197 drm_connector_list_iter_begin(dev, &conn_iter);
198 drm_for_each_connector_iter(connector, &conn_iter) {
199 if (connector->polled != DRM_CONNECTOR_POLL_HPD)
200 continue;
201
202 intel_connector = to_intel_connector(connector);
203 intel_encoder = intel_connector->encoder;
204 if (!intel_encoder)
205 continue;
206
207 pin = intel_encoder->hpd_pin;
208 if (pin == HPD_NONE ||
209 dev_priv->hotplug.stats[pin].state != HPD_MARK_DISABLED)
210 continue;
211
212 DRM_INFO("HPD interrupt storm detected on connector %s: "
213 "switching from hotplug detection to polling\n",
214 connector->name);
215
216 dev_priv->hotplug.stats[pin].state = HPD_DISABLED;
217 connector->polled = DRM_CONNECTOR_POLL_CONNECT
218 | DRM_CONNECTOR_POLL_DISCONNECT;
219 hpd_disabled = true;
220 }
221 drm_connector_list_iter_end(&conn_iter);
222
223 /* Enable polling and queue hotplug re-enabling. */
224 if (hpd_disabled) {
225 drm_kms_helper_poll_enable(dev);
226 mod_delayed_work(system_wq, &dev_priv->hotplug.reenable_work,
227 msecs_to_jiffies(HPD_STORM_REENABLE_DELAY));
228 }
229}
230
231static void intel_hpd_irq_storm_reenable_work(struct work_struct *work)
232{
233 struct drm_i915_private *dev_priv =
234 container_of(work, typeof(*dev_priv),
235 hotplug.reenable_work.work);
236 struct drm_device *dev = &dev_priv->drm;
237 intel_wakeref_t wakeref;
238 enum hpd_pin pin;
239
240 wakeref = intel_runtime_pm_get(&dev_priv->runtime_pm);
241
242 spin_lock_irq(&dev_priv->irq_lock);
243 for_each_hpd_pin(pin) {
244 struct drm_connector *connector;
245 struct drm_connector_list_iter conn_iter;
246
247 if (dev_priv->hotplug.stats[pin].state != HPD_DISABLED)
248 continue;
249
250 dev_priv->hotplug.stats[pin].state = HPD_ENABLED;
251
252 drm_connector_list_iter_begin(dev, &conn_iter);
253 drm_for_each_connector_iter(connector, &conn_iter) {
254 struct intel_connector *intel_connector = to_intel_connector(connector);
255
256 /* Don't check MST ports, they don't have pins */
257 if (!intel_connector->mst_port &&
258 intel_connector->encoder->hpd_pin == pin) {
259 if (connector->polled != intel_connector->polled)
260 DRM_DEBUG_DRIVER("Reenabling HPD on connector %s\n",
261 connector->name);
262 connector->polled = intel_connector->polled;
263 if (!connector->polled)
264 connector->polled = DRM_CONNECTOR_POLL_HPD;
265 }
266 }
267 drm_connector_list_iter_end(&conn_iter);
268 }
269 if (dev_priv->display_irqs_enabled && dev_priv->display.hpd_irq_setup)
270 dev_priv->display.hpd_irq_setup(dev_priv);
271 spin_unlock_irq(&dev_priv->irq_lock);
272
273 intel_runtime_pm_put(&dev_priv->runtime_pm, wakeref);
274}
275
276enum intel_hotplug_state
277intel_encoder_hotplug(struct intel_encoder *encoder,
278 struct intel_connector *connector,
279 bool irq_received)
280{
281 struct drm_device *dev = connector->base.dev;
282 enum drm_connector_status old_status;
283
284 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
285 old_status = connector->base.status;
286
287 connector->base.status =
288 drm_helper_probe_detect(&connector->base, NULL, false);
289
290 if (old_status == connector->base.status)
291 return INTEL_HOTPLUG_UNCHANGED;
292
293 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
294 connector->base.base.id,
295 connector->base.name,
296 drm_get_connector_status_name(old_status),
297 drm_get_connector_status_name(connector->base.status));
298
299 return INTEL_HOTPLUG_CHANGED;
300}
301
302static bool intel_encoder_has_hpd_pulse(struct intel_encoder *encoder)
303{
304 return intel_encoder_is_dig_port(encoder) &&
305 enc_to_dig_port(&encoder->base)->hpd_pulse != NULL;
306}
307
308static void i915_digport_work_func(struct work_struct *work)
309{
310 struct drm_i915_private *dev_priv =
311 container_of(work, struct drm_i915_private, hotplug.dig_port_work);
312 u32 long_port_mask, short_port_mask;
313 struct intel_encoder *encoder;
314 u32 old_bits = 0;
315
316 spin_lock_irq(&dev_priv->irq_lock);
317 long_port_mask = dev_priv->hotplug.long_port_mask;
318 dev_priv->hotplug.long_port_mask = 0;
319 short_port_mask = dev_priv->hotplug.short_port_mask;
320 dev_priv->hotplug.short_port_mask = 0;
321 spin_unlock_irq(&dev_priv->irq_lock);
322
323 for_each_intel_encoder(&dev_priv->drm, encoder) {
324 struct intel_digital_port *dig_port;
325 enum port port = encoder->port;
326 bool long_hpd, short_hpd;
327 enum irqreturn ret;
328
329 if (!intel_encoder_has_hpd_pulse(encoder))
330 continue;
331
332 long_hpd = long_port_mask & BIT(port);
333 short_hpd = short_port_mask & BIT(port);
334
335 if (!long_hpd && !short_hpd)
336 continue;
337
338 dig_port = enc_to_dig_port(&encoder->base);
339
340 ret = dig_port->hpd_pulse(dig_port, long_hpd);
341 if (ret == IRQ_NONE) {
342 /* fall back to old school hpd */
343 old_bits |= BIT(encoder->hpd_pin);
344 }
345 }
346
347 if (old_bits) {
348 spin_lock_irq(&dev_priv->irq_lock);
349 dev_priv->hotplug.event_bits |= old_bits;
350 spin_unlock_irq(&dev_priv->irq_lock);
351 queue_delayed_work(system_wq, &dev_priv->hotplug.hotplug_work, 0);
352 }
353}
354
355/*
356 * Handle hotplug events outside the interrupt handler proper.
357 */
358static void i915_hotplug_work_func(struct work_struct *work)
359{
360 struct drm_i915_private *dev_priv =
361 container_of(work, struct drm_i915_private,
362 hotplug.hotplug_work.work);
363 struct drm_device *dev = &dev_priv->drm;
364 struct intel_connector *intel_connector;
365 struct intel_encoder *intel_encoder;
366 struct drm_connector *connector;
367 struct drm_connector_list_iter conn_iter;
368 u32 changed = 0, retry = 0;
369 u32 hpd_event_bits;
370 u32 hpd_retry_bits;
371
372 mutex_lock(&dev->mode_config.mutex);
373 DRM_DEBUG_KMS("running encoder hotplug functions\n");
374
375 spin_lock_irq(&dev_priv->irq_lock);
376
377 hpd_event_bits = dev_priv->hotplug.event_bits;
378 dev_priv->hotplug.event_bits = 0;
379 hpd_retry_bits = dev_priv->hotplug.retry_bits;
380 dev_priv->hotplug.retry_bits = 0;
381
382 /* Enable polling for connectors which had HPD IRQ storms */
383 intel_hpd_irq_storm_switch_to_polling(dev_priv);
384
385 spin_unlock_irq(&dev_priv->irq_lock);
386
387 drm_connector_list_iter_begin(dev, &conn_iter);
388 drm_for_each_connector_iter(connector, &conn_iter) {
389 u32 hpd_bit;
390
391 intel_connector = to_intel_connector(connector);
392 if (!intel_connector->encoder)
393 continue;
394 intel_encoder = intel_connector->encoder;
395 hpd_bit = BIT(intel_encoder->hpd_pin);
396 if ((hpd_event_bits | hpd_retry_bits) & hpd_bit) {
397 DRM_DEBUG_KMS("Connector %s (pin %i) received hotplug event.\n",
398 connector->name, intel_encoder->hpd_pin);
399
400 switch (intel_encoder->hotplug(intel_encoder,
401 intel_connector,
402 hpd_event_bits & hpd_bit)) {
403 case INTEL_HOTPLUG_UNCHANGED:
404 break;
405 case INTEL_HOTPLUG_CHANGED:
406 changed |= hpd_bit;
407 break;
408 case INTEL_HOTPLUG_RETRY:
409 retry |= hpd_bit;
410 break;
411 }
412 }
413 }
414 drm_connector_list_iter_end(&conn_iter);
415 mutex_unlock(&dev->mode_config.mutex);
416
417 if (changed)
418 drm_kms_helper_hotplug_event(dev);
419
420 /* Remove shared HPD pins that have changed */
421 retry &= ~changed;
422 if (retry) {
423 spin_lock_irq(&dev_priv->irq_lock);
424 dev_priv->hotplug.retry_bits |= retry;
425 spin_unlock_irq(&dev_priv->irq_lock);
426
427 mod_delayed_work(system_wq, &dev_priv->hotplug.hotplug_work,
428 msecs_to_jiffies(HPD_RETRY_DELAY));
429 }
430}
431
432
433/**
434 * intel_hpd_irq_handler - main hotplug irq handler
435 * @dev_priv: drm_i915_private
436 * @pin_mask: a mask of hpd pins that have triggered the irq
437 * @long_mask: a mask of hpd pins that may be long hpd pulses
438 *
439 * This is the main hotplug irq handler for all platforms. The platform specific
440 * irq handlers call the platform specific hotplug irq handlers, which read and
441 * decode the appropriate registers into bitmasks about hpd pins that have
442 * triggered (@pin_mask), and which of those pins may be long pulses
443 * (@long_mask). The @long_mask is ignored if the port corresponding to the pin
444 * is not a digital port.
445 *
446 * Here, we do hotplug irq storm detection and mitigation, and pass further
447 * processing to appropriate bottom halves.
448 */
449void intel_hpd_irq_handler(struct drm_i915_private *dev_priv,
450 u32 pin_mask, u32 long_mask)
451{
452 struct intel_encoder *encoder;
453 bool storm_detected = false;
454 bool queue_dig = false, queue_hp = false;
455 u32 long_hpd_pulse_mask = 0;
456 u32 short_hpd_pulse_mask = 0;
457 enum hpd_pin pin;
458
459 if (!pin_mask)
460 return;
461
462 spin_lock(&dev_priv->irq_lock);
463
464 /*
465 * Determine whether ->hpd_pulse() exists for each pin, and
466 * whether we have a short or a long pulse. This is needed
467 * as each pin may have up to two encoders (HDMI and DP) and
468 * only the one of them (DP) will have ->hpd_pulse().
469 */
470 for_each_intel_encoder(&dev_priv->drm, encoder) {
471 bool has_hpd_pulse = intel_encoder_has_hpd_pulse(encoder);
472 enum port port = encoder->port;
473 bool long_hpd;
474
475 pin = encoder->hpd_pin;
476 if (!(BIT(pin) & pin_mask))
477 continue;
478
479 if (!has_hpd_pulse)
480 continue;
481
482 long_hpd = long_mask & BIT(pin);
483
484 DRM_DEBUG_DRIVER("digital hpd port %c - %s\n", port_name(port),
485 long_hpd ? "long" : "short");
486 queue_dig = true;
487
488 if (long_hpd) {
489 long_hpd_pulse_mask |= BIT(pin);
490 dev_priv->hotplug.long_port_mask |= BIT(port);
491 } else {
492 short_hpd_pulse_mask |= BIT(pin);
493 dev_priv->hotplug.short_port_mask |= BIT(port);
494 }
495 }
496
497 /* Now process each pin just once */
498 for_each_hpd_pin(pin) {
499 bool long_hpd;
500
501 if (!(BIT(pin) & pin_mask))
502 continue;
503
504 if (dev_priv->hotplug.stats[pin].state == HPD_DISABLED) {
505 /*
506 * On GMCH platforms the interrupt mask bits only
507 * prevent irq generation, not the setting of the
508 * hotplug bits itself. So only WARN about unexpected
509 * interrupts on saner platforms.
510 */
511 WARN_ONCE(!HAS_GMCH(dev_priv),
512 "Received HPD interrupt on pin %d although disabled\n", pin);
513 continue;
514 }
515
516 if (dev_priv->hotplug.stats[pin].state != HPD_ENABLED)
517 continue;
518
519 /*
520 * Delegate to ->hpd_pulse() if one of the encoders for this
521 * pin has it, otherwise let the hotplug_work deal with this
522 * pin directly.
523 */
524 if (((short_hpd_pulse_mask | long_hpd_pulse_mask) & BIT(pin))) {
525 long_hpd = long_hpd_pulse_mask & BIT(pin);
526 } else {
527 dev_priv->hotplug.event_bits |= BIT(pin);
528 long_hpd = true;
529 queue_hp = true;
530 }
531
532 if (intel_hpd_irq_storm_detect(dev_priv, pin, long_hpd)) {
533 dev_priv->hotplug.event_bits &= ~BIT(pin);
534 storm_detected = true;
535 queue_hp = true;
536 }
537 }
538
539 /*
540 * Disable any IRQs that storms were detected on. Polling enablement
541 * happens later in our hotplug work.
542 */
543 if (storm_detected && dev_priv->display_irqs_enabled)
544 dev_priv->display.hpd_irq_setup(dev_priv);
545 spin_unlock(&dev_priv->irq_lock);
546
547 /*
548 * Our hotplug handler can grab modeset locks (by calling down into the
549 * fb helpers). Hence it must not be run on our own dev-priv->wq work
550 * queue for otherwise the flush_work in the pageflip code will
551 * deadlock.
552 */
553 if (queue_dig)
554 queue_work(dev_priv->hotplug.dp_wq, &dev_priv->hotplug.dig_port_work);
555 if (queue_hp)
556 queue_delayed_work(system_wq, &dev_priv->hotplug.hotplug_work, 0);
557}
558
559/**
560 * intel_hpd_init - initializes and enables hpd support
561 * @dev_priv: i915 device instance
562 *
563 * This function enables the hotplug support. It requires that interrupts have
564 * already been enabled with intel_irq_init_hw(). From this point on hotplug and
565 * poll request can run concurrently to other code, so locking rules must be
566 * obeyed.
567 *
568 * This is a separate step from interrupt enabling to simplify the locking rules
569 * in the driver load and resume code.
570 *
571 * Also see: intel_hpd_poll_init(), which enables connector polling
572 */
573void intel_hpd_init(struct drm_i915_private *dev_priv)
574{
575 int i;
576
577 for_each_hpd_pin(i) {
578 dev_priv->hotplug.stats[i].count = 0;
579 dev_priv->hotplug.stats[i].state = HPD_ENABLED;
580 }
581
582 WRITE_ONCE(dev_priv->hotplug.poll_enabled, false);
583 schedule_work(&dev_priv->hotplug.poll_init_work);
584
585 /*
586 * Interrupt setup is already guaranteed to be single-threaded, this is
587 * just to make the assert_spin_locked checks happy.
588 */
589 if (dev_priv->display_irqs_enabled && dev_priv->display.hpd_irq_setup) {
590 spin_lock_irq(&dev_priv->irq_lock);
591 if (dev_priv->display_irqs_enabled)
592 dev_priv->display.hpd_irq_setup(dev_priv);
593 spin_unlock_irq(&dev_priv->irq_lock);
594 }
595}
596
597static void i915_hpd_poll_init_work(struct work_struct *work)
598{
599 struct drm_i915_private *dev_priv =
600 container_of(work, struct drm_i915_private,
601 hotplug.poll_init_work);
602 struct drm_device *dev = &dev_priv->drm;
603 struct drm_connector *connector;
604 struct drm_connector_list_iter conn_iter;
605 bool enabled;
606
607 mutex_lock(&dev->mode_config.mutex);
608
609 enabled = READ_ONCE(dev_priv->hotplug.poll_enabled);
610
611 drm_connector_list_iter_begin(dev, &conn_iter);
612 drm_for_each_connector_iter(connector, &conn_iter) {
613 struct intel_connector *intel_connector =
614 to_intel_connector(connector);
615 connector->polled = intel_connector->polled;
616
617 /* MST has a dynamic intel_connector->encoder and it's reprobing
618 * is all handled by the MST helpers. */
619 if (intel_connector->mst_port)
620 continue;
621
622 if (!connector->polled && I915_HAS_HOTPLUG(dev_priv) &&
623 intel_connector->encoder->hpd_pin > HPD_NONE) {
624 connector->polled = enabled ?
625 DRM_CONNECTOR_POLL_CONNECT |
626 DRM_CONNECTOR_POLL_DISCONNECT :
627 DRM_CONNECTOR_POLL_HPD;
628 }
629 }
630 drm_connector_list_iter_end(&conn_iter);
631
632 if (enabled)
633 drm_kms_helper_poll_enable(dev);
634
635 mutex_unlock(&dev->mode_config.mutex);
636
637 /*
638 * We might have missed any hotplugs that happened while we were
639 * in the middle of disabling polling
640 */
641 if (!enabled)
642 drm_helper_hpd_irq_event(dev);
643}
644
645/**
646 * intel_hpd_poll_init - enables/disables polling for connectors with hpd
647 * @dev_priv: i915 device instance
648 *
649 * This function enables polling for all connectors, regardless of whether or
650 * not they support hotplug detection. Under certain conditions HPD may not be
651 * functional. On most Intel GPUs, this happens when we enter runtime suspend.
652 * On Valleyview and Cherryview systems, this also happens when we shut off all
653 * of the powerwells.
654 *
655 * Since this function can get called in contexts where we're already holding
656 * dev->mode_config.mutex, we do the actual hotplug enabling in a seperate
657 * worker.
658 *
659 * Also see: intel_hpd_init(), which restores hpd handling.
660 */
661void intel_hpd_poll_init(struct drm_i915_private *dev_priv)
662{
663 WRITE_ONCE(dev_priv->hotplug.poll_enabled, true);
664
665 /*
666 * We might already be holding dev->mode_config.mutex, so do this in a
667 * seperate worker
668 * As well, there's no issue if we race here since we always reschedule
669 * this worker anyway
670 */
671 schedule_work(&dev_priv->hotplug.poll_init_work);
672}
673
674void intel_hpd_init_work(struct drm_i915_private *dev_priv)
675{
676 INIT_DELAYED_WORK(&dev_priv->hotplug.hotplug_work,
677 i915_hotplug_work_func);
678 INIT_WORK(&dev_priv->hotplug.dig_port_work, i915_digport_work_func);
679 INIT_WORK(&dev_priv->hotplug.poll_init_work, i915_hpd_poll_init_work);
680 INIT_DELAYED_WORK(&dev_priv->hotplug.reenable_work,
681 intel_hpd_irq_storm_reenable_work);
682}
683
684void intel_hpd_cancel_work(struct drm_i915_private *dev_priv)
685{
686 spin_lock_irq(&dev_priv->irq_lock);
687
688 dev_priv->hotplug.long_port_mask = 0;
689 dev_priv->hotplug.short_port_mask = 0;
690 dev_priv->hotplug.event_bits = 0;
691 dev_priv->hotplug.retry_bits = 0;
692
693 spin_unlock_irq(&dev_priv->irq_lock);
694
695 cancel_work_sync(&dev_priv->hotplug.dig_port_work);
696 cancel_delayed_work_sync(&dev_priv->hotplug.hotplug_work);
697 cancel_work_sync(&dev_priv->hotplug.poll_init_work);
698 cancel_delayed_work_sync(&dev_priv->hotplug.reenable_work);
699}
700
701bool intel_hpd_disable(struct drm_i915_private *dev_priv, enum hpd_pin pin)
702{
703 bool ret = false;
704
705 if (pin == HPD_NONE)
706 return false;
707
708 spin_lock_irq(&dev_priv->irq_lock);
709 if (dev_priv->hotplug.stats[pin].state == HPD_ENABLED) {
710 dev_priv->hotplug.stats[pin].state = HPD_DISABLED;
711 ret = true;
712 }
713 spin_unlock_irq(&dev_priv->irq_lock);
714
715 return ret;
716}
717
718void intel_hpd_enable(struct drm_i915_private *dev_priv, enum hpd_pin pin)
719{
720 if (pin == HPD_NONE)
721 return;
722
723 spin_lock_irq(&dev_priv->irq_lock);
724 dev_priv->hotplug.stats[pin].state = HPD_ENABLED;
725 spin_unlock_irq(&dev_priv->irq_lock);
726}