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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 "i915_drv.h"
27#include "intel_display_types.h"
28#include "intel_hotplug.h"
29
30/**
31 * DOC: Hotplug
32 *
33 * Simply put, hotplug occurs when a display is connected to or disconnected
34 * from the system. However, there may be adapters and docking stations and
35 * Display Port short pulses and MST devices involved, complicating matters.
36 *
37 * Hotplug in i915 is handled in many different levels of abstraction.
38 *
39 * The platform dependent interrupt handling code in i915_irq.c enables,
40 * disables, and does preliminary handling of the interrupts. The interrupt
41 * handlers gather the hotplug detect (HPD) information from relevant registers
42 * into a platform independent mask of hotplug pins that have fired.
43 *
44 * The platform independent interrupt handler intel_hpd_irq_handler() in
45 * intel_hotplug.c does hotplug irq storm detection and mitigation, and passes
46 * further processing to appropriate bottom halves (Display Port specific and
47 * regular hotplug).
48 *
49 * The Display Port work function i915_digport_work_func() calls into
50 * intel_dp_hpd_pulse() via hooks, which handles DP short pulses and DP MST long
51 * pulses, with failures and non-MST long pulses triggering regular hotplug
52 * processing on the connector.
53 *
54 * The regular hotplug work function i915_hotplug_work_func() calls connector
55 * detect hooks, and, if connector status changes, triggers sending of hotplug
56 * uevent to userspace via drm_kms_helper_hotplug_event().
57 *
58 * Finally, the userspace is responsible for triggering a modeset upon receiving
59 * the hotplug uevent, disabling or enabling the crtc as needed.
60 *
61 * The hotplug interrupt storm detection and mitigation code keeps track of the
62 * number of interrupts per hotplug pin per a period of time, and if the number
63 * of interrupts exceeds a certain threshold, the interrupt is disabled for a
64 * while before being re-enabled. The intention is to mitigate issues raising
65 * from broken hardware triggering massive amounts of interrupts and grinding
66 * the system to a halt.
67 *
68 * Current implementation expects that hotplug interrupt storm will not be
69 * seen when display port sink is connected, hence on platforms whose DP
70 * callback is handled by i915_digport_work_func reenabling of hpd is not
71 * performed (it was never expected to be disabled in the first place ;) )
72 * this is specific to DP sinks handled by this routine and any other display
73 * such as HDMI or DVI enabled on the same port will have proper logic since
74 * it will use i915_hotplug_work_func where this logic is handled.
75 */
76
77/**
78 * intel_hpd_pin_default - return default pin associated with certain port.
79 * @dev_priv: private driver data pointer
80 * @port: the hpd port to get associated pin
81 *
82 * It is only valid and used by digital port encoder.
83 *
84 * Return pin that is associatade with @port and HDP_NONE if no pin is
85 * hard associated with that @port.
86 */
87enum hpd_pin intel_hpd_pin_default(struct drm_i915_private *dev_priv,
88 enum port port)
89{
90 enum phy phy = intel_port_to_phy(dev_priv, port);
91
92 /*
93 * RKL + TGP PCH is a special case; we effectively choose the hpd_pin
94 * based on the DDI rather than the PHY (i.e., the last two outputs
95 * shold be HPD_PORT_{D,E} rather than {C,D}. Note that this differs
96 * from the behavior of both TGL+TGP and RKL+CMP.
97 */
98 if (IS_ROCKETLAKE(dev_priv) && HAS_PCH_TGP(dev_priv))
99 return HPD_PORT_A + port - PORT_A;
100
101 switch (phy) {
102 case PHY_F:
103 return IS_CNL_WITH_PORT_F(dev_priv) ? HPD_PORT_E : HPD_PORT_F;
104 case PHY_A ... PHY_E:
105 case PHY_G ... PHY_I:
106 return HPD_PORT_A + phy - PHY_A;
107 default:
108 MISSING_CASE(phy);
109 return HPD_NONE;
110 }
111}
112
113#define HPD_STORM_DETECT_PERIOD 1000
114#define HPD_STORM_REENABLE_DELAY (2 * 60 * 1000)
115#define HPD_RETRY_DELAY 1000
116
117static enum hpd_pin
118intel_connector_hpd_pin(struct intel_connector *connector)
119{
120 struct intel_encoder *encoder = intel_attached_encoder(connector);
121
122 /*
123 * MST connectors get their encoder attached dynamically
124 * so need to make sure we have an encoder here. But since
125 * MST encoders have their hpd_pin set to HPD_NONE we don't
126 * have to special case them beyond that.
127 */
128 return encoder ? encoder->hpd_pin : HPD_NONE;
129}
130
131/**
132 * intel_hpd_irq_storm_detect - gather stats and detect HPD IRQ storm on a pin
133 * @dev_priv: private driver data pointer
134 * @pin: the pin to gather stats on
135 * @long_hpd: whether the HPD IRQ was long or short
136 *
137 * Gather stats about HPD IRQs from the specified @pin, and detect IRQ
138 * storms. Only the pin specific stats and state are changed, the caller is
139 * responsible for further action.
140 *
141 * The number of IRQs that are allowed within @HPD_STORM_DETECT_PERIOD is
142 * stored in @dev_priv->hotplug.hpd_storm_threshold which defaults to
143 * @HPD_STORM_DEFAULT_THRESHOLD. Long IRQs count as +10 to this threshold, and
144 * short IRQs count as +1. If this threshold is exceeded, it's considered an
145 * IRQ storm and the IRQ state is set to @HPD_MARK_DISABLED.
146 *
147 * By default, most systems will only count long IRQs towards
148 * &dev_priv->hotplug.hpd_storm_threshold. However, some older systems also
149 * suffer from short IRQ storms and must also track these. Because short IRQ
150 * storms are naturally caused by sideband interactions with DP MST devices,
151 * short IRQ detection is only enabled for systems without DP MST support.
152 * Systems which are new enough to support DP MST are far less likely to
153 * suffer from IRQ storms at all, so this is fine.
154 *
155 * The HPD threshold can be controlled through i915_hpd_storm_ctl in debugfs,
156 * and should only be adjusted for automated hotplug testing.
157 *
158 * Return true if an IRQ storm was detected on @pin.
159 */
160static bool intel_hpd_irq_storm_detect(struct drm_i915_private *dev_priv,
161 enum hpd_pin pin, bool long_hpd)
162{
163 struct i915_hotplug *hpd = &dev_priv->hotplug;
164 unsigned long start = hpd->stats[pin].last_jiffies;
165 unsigned long end = start + msecs_to_jiffies(HPD_STORM_DETECT_PERIOD);
166 const int increment = long_hpd ? 10 : 1;
167 const int threshold = hpd->hpd_storm_threshold;
168 bool storm = false;
169
170 if (!threshold ||
171 (!long_hpd && !dev_priv->hotplug.hpd_short_storm_enabled))
172 return false;
173
174 if (!time_in_range(jiffies, start, end)) {
175 hpd->stats[pin].last_jiffies = jiffies;
176 hpd->stats[pin].count = 0;
177 }
178
179 hpd->stats[pin].count += increment;
180 if (hpd->stats[pin].count > threshold) {
181 hpd->stats[pin].state = HPD_MARK_DISABLED;
182 drm_dbg_kms(&dev_priv->drm,
183 "HPD interrupt storm detected on PIN %d\n", pin);
184 storm = true;
185 } else {
186 drm_dbg_kms(&dev_priv->drm,
187 "Received HPD interrupt on PIN %d - cnt: %d\n",
188 pin,
189 hpd->stats[pin].count);
190 }
191
192 return storm;
193}
194
195static void
196intel_hpd_irq_storm_switch_to_polling(struct drm_i915_private *dev_priv)
197{
198 struct drm_device *dev = &dev_priv->drm;
199 struct drm_connector_list_iter conn_iter;
200 struct intel_connector *connector;
201 bool hpd_disabled = false;
202
203 lockdep_assert_held(&dev_priv->irq_lock);
204
205 drm_connector_list_iter_begin(dev, &conn_iter);
206 for_each_intel_connector_iter(connector, &conn_iter) {
207 enum hpd_pin pin;
208
209 if (connector->base.polled != DRM_CONNECTOR_POLL_HPD)
210 continue;
211
212 pin = intel_connector_hpd_pin(connector);
213 if (pin == HPD_NONE ||
214 dev_priv->hotplug.stats[pin].state != HPD_MARK_DISABLED)
215 continue;
216
217 drm_info(&dev_priv->drm,
218 "HPD interrupt storm detected on connector %s: "
219 "switching from hotplug detection to polling\n",
220 connector->base.name);
221
222 dev_priv->hotplug.stats[pin].state = HPD_DISABLED;
223 connector->base.polled = DRM_CONNECTOR_POLL_CONNECT |
224 DRM_CONNECTOR_POLL_DISCONNECT;
225 hpd_disabled = true;
226 }
227 drm_connector_list_iter_end(&conn_iter);
228
229 /* Enable polling and queue hotplug re-enabling. */
230 if (hpd_disabled) {
231 drm_kms_helper_poll_enable(dev);
232 mod_delayed_work(system_wq, &dev_priv->hotplug.reenable_work,
233 msecs_to_jiffies(HPD_STORM_REENABLE_DELAY));
234 }
235}
236
237static void intel_hpd_irq_storm_reenable_work(struct work_struct *work)
238{
239 struct drm_i915_private *dev_priv =
240 container_of(work, typeof(*dev_priv),
241 hotplug.reenable_work.work);
242 struct drm_device *dev = &dev_priv->drm;
243 struct drm_connector_list_iter conn_iter;
244 struct intel_connector *connector;
245 intel_wakeref_t wakeref;
246 enum hpd_pin pin;
247
248 wakeref = intel_runtime_pm_get(&dev_priv->runtime_pm);
249
250 spin_lock_irq(&dev_priv->irq_lock);
251
252 drm_connector_list_iter_begin(dev, &conn_iter);
253 for_each_intel_connector_iter(connector, &conn_iter) {
254 pin = intel_connector_hpd_pin(connector);
255 if (pin == HPD_NONE ||
256 dev_priv->hotplug.stats[pin].state != HPD_DISABLED)
257 continue;
258
259 if (connector->base.polled != connector->polled)
260 drm_dbg(&dev_priv->drm,
261 "Reenabling HPD on connector %s\n",
262 connector->base.name);
263 connector->base.polled = connector->polled;
264 }
265 drm_connector_list_iter_end(&conn_iter);
266
267 for_each_hpd_pin(pin) {
268 if (dev_priv->hotplug.stats[pin].state == HPD_DISABLED)
269 dev_priv->hotplug.stats[pin].state = HPD_ENABLED;
270 }
271
272 if (dev_priv->display_irqs_enabled && dev_priv->display.hpd_irq_setup)
273 dev_priv->display.hpd_irq_setup(dev_priv);
274
275 spin_unlock_irq(&dev_priv->irq_lock);
276
277 intel_runtime_pm_put(&dev_priv->runtime_pm, wakeref);
278}
279
280enum intel_hotplug_state
281intel_encoder_hotplug(struct intel_encoder *encoder,
282 struct intel_connector *connector)
283{
284 struct drm_device *dev = connector->base.dev;
285 enum drm_connector_status old_status;
286 u64 old_epoch_counter;
287 bool ret = false;
288
289 drm_WARN_ON(dev, !mutex_is_locked(&dev->mode_config.mutex));
290 old_status = connector->base.status;
291 old_epoch_counter = connector->base.epoch_counter;
292
293 connector->base.status =
294 drm_helper_probe_detect(&connector->base, NULL, false);
295
296 if (old_epoch_counter != connector->base.epoch_counter)
297 ret = true;
298
299 if (ret) {
300 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s (epoch counter %llu->%llu)\n",
301 connector->base.base.id,
302 connector->base.name,
303 drm_get_connector_status_name(old_status),
304 drm_get_connector_status_name(connector->base.status),
305 old_epoch_counter,
306 connector->base.epoch_counter);
307 return INTEL_HOTPLUG_CHANGED;
308 }
309 return INTEL_HOTPLUG_UNCHANGED;
310}
311
312static bool intel_encoder_has_hpd_pulse(struct intel_encoder *encoder)
313{
314 return intel_encoder_is_dig_port(encoder) &&
315 enc_to_dig_port(encoder)->hpd_pulse != NULL;
316}
317
318static void i915_digport_work_func(struct work_struct *work)
319{
320 struct drm_i915_private *dev_priv =
321 container_of(work, struct drm_i915_private, hotplug.dig_port_work);
322 u32 long_port_mask, short_port_mask;
323 struct intel_encoder *encoder;
324 u32 old_bits = 0;
325
326 spin_lock_irq(&dev_priv->irq_lock);
327 long_port_mask = dev_priv->hotplug.long_port_mask;
328 dev_priv->hotplug.long_port_mask = 0;
329 short_port_mask = dev_priv->hotplug.short_port_mask;
330 dev_priv->hotplug.short_port_mask = 0;
331 spin_unlock_irq(&dev_priv->irq_lock);
332
333 for_each_intel_encoder(&dev_priv->drm, encoder) {
334 struct intel_digital_port *dig_port;
335 enum port port = encoder->port;
336 bool long_hpd, short_hpd;
337 enum irqreturn ret;
338
339 if (!intel_encoder_has_hpd_pulse(encoder))
340 continue;
341
342 long_hpd = long_port_mask & BIT(port);
343 short_hpd = short_port_mask & BIT(port);
344
345 if (!long_hpd && !short_hpd)
346 continue;
347
348 dig_port = enc_to_dig_port(encoder);
349
350 ret = dig_port->hpd_pulse(dig_port, long_hpd);
351 if (ret == IRQ_NONE) {
352 /* fall back to old school hpd */
353 old_bits |= BIT(encoder->hpd_pin);
354 }
355 }
356
357 if (old_bits) {
358 spin_lock_irq(&dev_priv->irq_lock);
359 dev_priv->hotplug.event_bits |= old_bits;
360 spin_unlock_irq(&dev_priv->irq_lock);
361 queue_delayed_work(system_wq, &dev_priv->hotplug.hotplug_work, 0);
362 }
363}
364
365/**
366 * intel_hpd_trigger_irq - trigger an hpd irq event for a port
367 * @dig_port: digital port
368 *
369 * Trigger an HPD interrupt event for the given port, emulating a short pulse
370 * generated by the sink, and schedule the dig port work to handle it.
371 */
372void intel_hpd_trigger_irq(struct intel_digital_port *dig_port)
373{
374 struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
375
376 spin_lock_irq(&i915->irq_lock);
377 i915->hotplug.short_port_mask |= BIT(dig_port->base.port);
378 spin_unlock_irq(&i915->irq_lock);
379
380 queue_work(i915->hotplug.dp_wq, &i915->hotplug.dig_port_work);
381}
382
383/*
384 * Handle hotplug events outside the interrupt handler proper.
385 */
386static void i915_hotplug_work_func(struct work_struct *work)
387{
388 struct drm_i915_private *dev_priv =
389 container_of(work, struct drm_i915_private,
390 hotplug.hotplug_work.work);
391 struct drm_device *dev = &dev_priv->drm;
392 struct drm_connector_list_iter conn_iter;
393 struct intel_connector *connector;
394 u32 changed = 0, retry = 0;
395 u32 hpd_event_bits;
396 u32 hpd_retry_bits;
397
398 mutex_lock(&dev->mode_config.mutex);
399 drm_dbg_kms(&dev_priv->drm, "running encoder hotplug functions\n");
400
401 spin_lock_irq(&dev_priv->irq_lock);
402
403 hpd_event_bits = dev_priv->hotplug.event_bits;
404 dev_priv->hotplug.event_bits = 0;
405 hpd_retry_bits = dev_priv->hotplug.retry_bits;
406 dev_priv->hotplug.retry_bits = 0;
407
408 /* Enable polling for connectors which had HPD IRQ storms */
409 intel_hpd_irq_storm_switch_to_polling(dev_priv);
410
411 spin_unlock_irq(&dev_priv->irq_lock);
412
413 drm_connector_list_iter_begin(dev, &conn_iter);
414 for_each_intel_connector_iter(connector, &conn_iter) {
415 enum hpd_pin pin;
416 u32 hpd_bit;
417
418 pin = intel_connector_hpd_pin(connector);
419 if (pin == HPD_NONE)
420 continue;
421
422 hpd_bit = BIT(pin);
423 if ((hpd_event_bits | hpd_retry_bits) & hpd_bit) {
424 struct intel_encoder *encoder =
425 intel_attached_encoder(connector);
426
427 if (hpd_event_bits & hpd_bit)
428 connector->hotplug_retries = 0;
429 else
430 connector->hotplug_retries++;
431
432 drm_dbg_kms(&dev_priv->drm,
433 "Connector %s (pin %i) received hotplug event. (retry %d)\n",
434 connector->base.name, pin,
435 connector->hotplug_retries);
436
437 switch (encoder->hotplug(encoder, connector)) {
438 case INTEL_HOTPLUG_UNCHANGED:
439 break;
440 case INTEL_HOTPLUG_CHANGED:
441 changed |= hpd_bit;
442 break;
443 case INTEL_HOTPLUG_RETRY:
444 retry |= hpd_bit;
445 break;
446 }
447 }
448 }
449 drm_connector_list_iter_end(&conn_iter);
450 mutex_unlock(&dev->mode_config.mutex);
451
452 if (changed)
453 drm_kms_helper_hotplug_event(dev);
454
455 /* Remove shared HPD pins that have changed */
456 retry &= ~changed;
457 if (retry) {
458 spin_lock_irq(&dev_priv->irq_lock);
459 dev_priv->hotplug.retry_bits |= retry;
460 spin_unlock_irq(&dev_priv->irq_lock);
461
462 mod_delayed_work(system_wq, &dev_priv->hotplug.hotplug_work,
463 msecs_to_jiffies(HPD_RETRY_DELAY));
464 }
465}
466
467
468/**
469 * intel_hpd_irq_handler - main hotplug irq handler
470 * @dev_priv: drm_i915_private
471 * @pin_mask: a mask of hpd pins that have triggered the irq
472 * @long_mask: a mask of hpd pins that may be long hpd pulses
473 *
474 * This is the main hotplug irq handler for all platforms. The platform specific
475 * irq handlers call the platform specific hotplug irq handlers, which read and
476 * decode the appropriate registers into bitmasks about hpd pins that have
477 * triggered (@pin_mask), and which of those pins may be long pulses
478 * (@long_mask). The @long_mask is ignored if the port corresponding to the pin
479 * is not a digital port.
480 *
481 * Here, we do hotplug irq storm detection and mitigation, and pass further
482 * processing to appropriate bottom halves.
483 */
484void intel_hpd_irq_handler(struct drm_i915_private *dev_priv,
485 u32 pin_mask, u32 long_mask)
486{
487 struct intel_encoder *encoder;
488 bool storm_detected = false;
489 bool queue_dig = false, queue_hp = false;
490 u32 long_hpd_pulse_mask = 0;
491 u32 short_hpd_pulse_mask = 0;
492 enum hpd_pin pin;
493
494 if (!pin_mask)
495 return;
496
497 spin_lock(&dev_priv->irq_lock);
498
499 /*
500 * Determine whether ->hpd_pulse() exists for each pin, and
501 * whether we have a short or a long pulse. This is needed
502 * as each pin may have up to two encoders (HDMI and DP) and
503 * only the one of them (DP) will have ->hpd_pulse().
504 */
505 for_each_intel_encoder(&dev_priv->drm, encoder) {
506 bool has_hpd_pulse = intel_encoder_has_hpd_pulse(encoder);
507 enum port port = encoder->port;
508 bool long_hpd;
509
510 pin = encoder->hpd_pin;
511 if (!(BIT(pin) & pin_mask))
512 continue;
513
514 if (!has_hpd_pulse)
515 continue;
516
517 long_hpd = long_mask & BIT(pin);
518
519 drm_dbg(&dev_priv->drm,
520 "digital hpd on [ENCODER:%d:%s] - %s\n",
521 encoder->base.base.id, encoder->base.name,
522 long_hpd ? "long" : "short");
523 queue_dig = true;
524
525 if (long_hpd) {
526 long_hpd_pulse_mask |= BIT(pin);
527 dev_priv->hotplug.long_port_mask |= BIT(port);
528 } else {
529 short_hpd_pulse_mask |= BIT(pin);
530 dev_priv->hotplug.short_port_mask |= BIT(port);
531 }
532 }
533
534 /* Now process each pin just once */
535 for_each_hpd_pin(pin) {
536 bool long_hpd;
537
538 if (!(BIT(pin) & pin_mask))
539 continue;
540
541 if (dev_priv->hotplug.stats[pin].state == HPD_DISABLED) {
542 /*
543 * On GMCH platforms the interrupt mask bits only
544 * prevent irq generation, not the setting of the
545 * hotplug bits itself. So only WARN about unexpected
546 * interrupts on saner platforms.
547 */
548 drm_WARN_ONCE(&dev_priv->drm, !HAS_GMCH(dev_priv),
549 "Received HPD interrupt on pin %d although disabled\n",
550 pin);
551 continue;
552 }
553
554 if (dev_priv->hotplug.stats[pin].state != HPD_ENABLED)
555 continue;
556
557 /*
558 * Delegate to ->hpd_pulse() if one of the encoders for this
559 * pin has it, otherwise let the hotplug_work deal with this
560 * pin directly.
561 */
562 if (((short_hpd_pulse_mask | long_hpd_pulse_mask) & BIT(pin))) {
563 long_hpd = long_hpd_pulse_mask & BIT(pin);
564 } else {
565 dev_priv->hotplug.event_bits |= BIT(pin);
566 long_hpd = true;
567 queue_hp = true;
568 }
569
570 if (intel_hpd_irq_storm_detect(dev_priv, pin, long_hpd)) {
571 dev_priv->hotplug.event_bits &= ~BIT(pin);
572 storm_detected = true;
573 queue_hp = true;
574 }
575 }
576
577 /*
578 * Disable any IRQs that storms were detected on. Polling enablement
579 * happens later in our hotplug work.
580 */
581 if (storm_detected && dev_priv->display_irqs_enabled)
582 dev_priv->display.hpd_irq_setup(dev_priv);
583 spin_unlock(&dev_priv->irq_lock);
584
585 /*
586 * Our hotplug handler can grab modeset locks (by calling down into the
587 * fb helpers). Hence it must not be run on our own dev-priv->wq work
588 * queue for otherwise the flush_work in the pageflip code will
589 * deadlock.
590 */
591 if (queue_dig)
592 queue_work(dev_priv->hotplug.dp_wq, &dev_priv->hotplug.dig_port_work);
593 if (queue_hp)
594 queue_delayed_work(system_wq, &dev_priv->hotplug.hotplug_work, 0);
595}
596
597/**
598 * intel_hpd_init - initializes and enables hpd support
599 * @dev_priv: i915 device instance
600 *
601 * This function enables the hotplug support. It requires that interrupts have
602 * already been enabled with intel_irq_init_hw(). From this point on hotplug and
603 * poll request can run concurrently to other code, so locking rules must be
604 * obeyed.
605 *
606 * This is a separate step from interrupt enabling to simplify the locking rules
607 * in the driver load and resume code.
608 *
609 * Also see: intel_hpd_poll_init(), which enables connector polling
610 */
611void intel_hpd_init(struct drm_i915_private *dev_priv)
612{
613 int i;
614
615 for_each_hpd_pin(i) {
616 dev_priv->hotplug.stats[i].count = 0;
617 dev_priv->hotplug.stats[i].state = HPD_ENABLED;
618 }
619
620 WRITE_ONCE(dev_priv->hotplug.poll_enabled, false);
621 schedule_work(&dev_priv->hotplug.poll_init_work);
622
623 /*
624 * Interrupt setup is already guaranteed to be single-threaded, this is
625 * just to make the assert_spin_locked checks happy.
626 */
627 if (dev_priv->display_irqs_enabled && dev_priv->display.hpd_irq_setup) {
628 spin_lock_irq(&dev_priv->irq_lock);
629 if (dev_priv->display_irqs_enabled)
630 dev_priv->display.hpd_irq_setup(dev_priv);
631 spin_unlock_irq(&dev_priv->irq_lock);
632 }
633}
634
635static void i915_hpd_poll_init_work(struct work_struct *work)
636{
637 struct drm_i915_private *dev_priv =
638 container_of(work, struct drm_i915_private,
639 hotplug.poll_init_work);
640 struct drm_device *dev = &dev_priv->drm;
641 struct drm_connector_list_iter conn_iter;
642 struct intel_connector *connector;
643 bool enabled;
644
645 mutex_lock(&dev->mode_config.mutex);
646
647 enabled = READ_ONCE(dev_priv->hotplug.poll_enabled);
648
649 drm_connector_list_iter_begin(dev, &conn_iter);
650 for_each_intel_connector_iter(connector, &conn_iter) {
651 enum hpd_pin pin;
652
653 pin = intel_connector_hpd_pin(connector);
654 if (pin == HPD_NONE)
655 continue;
656
657 connector->base.polled = connector->polled;
658
659 if (enabled && connector->base.polled == DRM_CONNECTOR_POLL_HPD)
660 connector->base.polled = DRM_CONNECTOR_POLL_CONNECT |
661 DRM_CONNECTOR_POLL_DISCONNECT;
662 }
663 drm_connector_list_iter_end(&conn_iter);
664
665 if (enabled)
666 drm_kms_helper_poll_enable(dev);
667
668 mutex_unlock(&dev->mode_config.mutex);
669
670 /*
671 * We might have missed any hotplugs that happened while we were
672 * in the middle of disabling polling
673 */
674 if (!enabled)
675 drm_helper_hpd_irq_event(dev);
676}
677
678/**
679 * intel_hpd_poll_init - enables/disables polling for connectors with hpd
680 * @dev_priv: i915 device instance
681 *
682 * This function enables polling for all connectors, regardless of whether or
683 * not they support hotplug detection. Under certain conditions HPD may not be
684 * functional. On most Intel GPUs, this happens when we enter runtime suspend.
685 * On Valleyview and Cherryview systems, this also happens when we shut off all
686 * of the powerwells.
687 *
688 * Since this function can get called in contexts where we're already holding
689 * dev->mode_config.mutex, we do the actual hotplug enabling in a seperate
690 * worker.
691 *
692 * Also see: intel_hpd_init(), which restores hpd handling.
693 */
694void intel_hpd_poll_init(struct drm_i915_private *dev_priv)
695{
696 WRITE_ONCE(dev_priv->hotplug.poll_enabled, true);
697
698 /*
699 * We might already be holding dev->mode_config.mutex, so do this in a
700 * seperate worker
701 * As well, there's no issue if we race here since we always reschedule
702 * this worker anyway
703 */
704 schedule_work(&dev_priv->hotplug.poll_init_work);
705}
706
707void intel_hpd_init_work(struct drm_i915_private *dev_priv)
708{
709 INIT_DELAYED_WORK(&dev_priv->hotplug.hotplug_work,
710 i915_hotplug_work_func);
711 INIT_WORK(&dev_priv->hotplug.dig_port_work, i915_digport_work_func);
712 INIT_WORK(&dev_priv->hotplug.poll_init_work, i915_hpd_poll_init_work);
713 INIT_DELAYED_WORK(&dev_priv->hotplug.reenable_work,
714 intel_hpd_irq_storm_reenable_work);
715}
716
717void intel_hpd_cancel_work(struct drm_i915_private *dev_priv)
718{
719 spin_lock_irq(&dev_priv->irq_lock);
720
721 dev_priv->hotplug.long_port_mask = 0;
722 dev_priv->hotplug.short_port_mask = 0;
723 dev_priv->hotplug.event_bits = 0;
724 dev_priv->hotplug.retry_bits = 0;
725
726 spin_unlock_irq(&dev_priv->irq_lock);
727
728 cancel_work_sync(&dev_priv->hotplug.dig_port_work);
729 cancel_delayed_work_sync(&dev_priv->hotplug.hotplug_work);
730 cancel_work_sync(&dev_priv->hotplug.poll_init_work);
731 cancel_delayed_work_sync(&dev_priv->hotplug.reenable_work);
732}
733
734bool intel_hpd_disable(struct drm_i915_private *dev_priv, enum hpd_pin pin)
735{
736 bool ret = false;
737
738 if (pin == HPD_NONE)
739 return false;
740
741 spin_lock_irq(&dev_priv->irq_lock);
742 if (dev_priv->hotplug.stats[pin].state == HPD_ENABLED) {
743 dev_priv->hotplug.stats[pin].state = HPD_DISABLED;
744 ret = true;
745 }
746 spin_unlock_irq(&dev_priv->irq_lock);
747
748 return ret;
749}
750
751void intel_hpd_enable(struct drm_i915_private *dev_priv, enum hpd_pin pin)
752{
753 if (pin == HPD_NONE)
754 return;
755
756 spin_lock_irq(&dev_priv->irq_lock);
757 dev_priv->hotplug.stats[pin].state = HPD_ENABLED;
758 spin_unlock_irq(&dev_priv->irq_lock);
759}