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77913b39 JN |
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/drmP.h> | |
27 | #include <drm/i915_drm.h> | |
28 | ||
29 | #include "i915_drv.h" | |
30 | #include "intel_drv.h" | |
31 | ||
32 | enum port intel_hpd_pin_to_port(enum hpd_pin pin) | |
33 | { | |
34 | switch (pin) { | |
35 | case HPD_PORT_B: | |
36 | return PORT_B; | |
37 | case HPD_PORT_C: | |
38 | return PORT_C; | |
39 | case HPD_PORT_D: | |
40 | return PORT_D; | |
41 | default: | |
42 | return PORT_A; /* no hpd */ | |
43 | } | |
44 | } | |
45 | ||
46 | #define HPD_STORM_DETECT_PERIOD 1000 | |
47 | #define HPD_STORM_THRESHOLD 5 | |
48 | #define HPD_STORM_REENABLE_DELAY (2 * 60 * 1000) | |
49 | ||
50 | /** | |
51 | * intel_hpd_irq_storm_detect - gather stats and detect HPD irq storm on a pin | |
52 | * @dev_priv: private driver data pointer | |
53 | * @pin: the pin to gather stats on | |
54 | * | |
55 | * Gather stats about HPD irqs from the specified @pin, and detect irq | |
56 | * storms. Only the pin specific stats and state are changed, the caller is | |
57 | * responsible for further action. | |
58 | * | |
59 | * @HPD_STORM_THRESHOLD irqs are allowed within @HPD_STORM_DETECT_PERIOD ms, | |
60 | * otherwise it's considered an irq storm, and the irq state is set to | |
61 | * @HPD_MARK_DISABLED. | |
62 | * | |
63 | * Return true if an irq storm was detected on @pin. | |
64 | */ | |
65 | static bool intel_hpd_irq_storm_detect(struct drm_i915_private *dev_priv, | |
66 | enum hpd_pin pin) | |
67 | { | |
68 | unsigned long start = dev_priv->hotplug.stats[pin].last_jiffies; | |
69 | unsigned long end = start + msecs_to_jiffies(HPD_STORM_DETECT_PERIOD); | |
70 | bool storm = false; | |
71 | ||
72 | if (!time_in_range(jiffies, start, end)) { | |
73 | dev_priv->hotplug.stats[pin].last_jiffies = jiffies; | |
74 | dev_priv->hotplug.stats[pin].count = 0; | |
75 | DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: 0\n", pin); | |
76 | } else if (dev_priv->hotplug.stats[pin].count > HPD_STORM_THRESHOLD) { | |
77 | dev_priv->hotplug.stats[pin].state = HPD_MARK_DISABLED; | |
78 | DRM_DEBUG_KMS("HPD interrupt storm detected on PIN %d\n", pin); | |
79 | storm = true; | |
80 | } else { | |
81 | dev_priv->hotplug.stats[pin].count++; | |
82 | DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: %d\n", pin, | |
83 | dev_priv->hotplug.stats[pin].count); | |
84 | } | |
85 | ||
86 | return storm; | |
87 | } | |
88 | ||
89 | static void intel_hpd_irq_storm_disable(struct drm_i915_private *dev_priv) | |
90 | { | |
91 | struct drm_device *dev = dev_priv->dev; | |
92 | struct drm_mode_config *mode_config = &dev->mode_config; | |
93 | struct intel_connector *intel_connector; | |
94 | struct intel_encoder *intel_encoder; | |
95 | struct drm_connector *connector; | |
96 | enum hpd_pin pin; | |
97 | bool hpd_disabled = false; | |
98 | ||
99 | assert_spin_locked(&dev_priv->irq_lock); | |
100 | ||
101 | list_for_each_entry(connector, &mode_config->connector_list, head) { | |
102 | if (connector->polled != DRM_CONNECTOR_POLL_HPD) | |
103 | continue; | |
104 | ||
105 | intel_connector = to_intel_connector(connector); | |
106 | intel_encoder = intel_connector->encoder; | |
107 | if (!intel_encoder) | |
108 | continue; | |
109 | ||
110 | pin = intel_encoder->hpd_pin; | |
111 | if (pin == HPD_NONE || | |
112 | dev_priv->hotplug.stats[pin].state != HPD_MARK_DISABLED) | |
113 | continue; | |
114 | ||
115 | DRM_INFO("HPD interrupt storm detected on connector %s: " | |
116 | "switching from hotplug detection to polling\n", | |
117 | connector->name); | |
118 | ||
119 | dev_priv->hotplug.stats[pin].state = HPD_DISABLED; | |
120 | connector->polled = DRM_CONNECTOR_POLL_CONNECT | |
121 | | DRM_CONNECTOR_POLL_DISCONNECT; | |
122 | hpd_disabled = true; | |
123 | } | |
124 | ||
125 | /* Enable polling and queue hotplug re-enabling. */ | |
126 | if (hpd_disabled) { | |
127 | drm_kms_helper_poll_enable(dev); | |
128 | mod_delayed_work(system_wq, &dev_priv->hotplug.reenable_work, | |
129 | msecs_to_jiffies(HPD_STORM_REENABLE_DELAY)); | |
130 | } | |
131 | } | |
132 | ||
133 | static void intel_hpd_irq_storm_reenable_work(struct work_struct *work) | |
134 | { | |
135 | struct drm_i915_private *dev_priv = | |
136 | container_of(work, typeof(*dev_priv), | |
137 | hotplug.reenable_work.work); | |
138 | struct drm_device *dev = dev_priv->dev; | |
139 | struct drm_mode_config *mode_config = &dev->mode_config; | |
140 | int i; | |
141 | ||
142 | intel_runtime_pm_get(dev_priv); | |
143 | ||
144 | spin_lock_irq(&dev_priv->irq_lock); | |
145 | for_each_hpd_pin(i) { | |
146 | struct drm_connector *connector; | |
147 | ||
148 | if (dev_priv->hotplug.stats[i].state != HPD_DISABLED) | |
149 | continue; | |
150 | ||
151 | dev_priv->hotplug.stats[i].state = HPD_ENABLED; | |
152 | ||
153 | list_for_each_entry(connector, &mode_config->connector_list, head) { | |
154 | struct intel_connector *intel_connector = to_intel_connector(connector); | |
155 | ||
156 | if (intel_connector->encoder->hpd_pin == i) { | |
157 | if (connector->polled != intel_connector->polled) | |
158 | DRM_DEBUG_DRIVER("Reenabling HPD on connector %s\n", | |
159 | connector->name); | |
160 | connector->polled = intel_connector->polled; | |
161 | if (!connector->polled) | |
162 | connector->polled = DRM_CONNECTOR_POLL_HPD; | |
163 | } | |
164 | } | |
165 | } | |
166 | if (dev_priv->display.hpd_irq_setup) | |
167 | dev_priv->display.hpd_irq_setup(dev); | |
168 | spin_unlock_irq(&dev_priv->irq_lock); | |
169 | ||
170 | intel_runtime_pm_put(dev_priv); | |
171 | } | |
172 | ||
173 | static bool intel_hpd_irq_event(struct drm_device *dev, | |
174 | struct drm_connector *connector) | |
175 | { | |
176 | enum drm_connector_status old_status; | |
177 | ||
178 | WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); | |
179 | old_status = connector->status; | |
180 | ||
181 | connector->status = connector->funcs->detect(connector, false); | |
182 | if (old_status == connector->status) | |
183 | return false; | |
184 | ||
185 | DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n", | |
186 | connector->base.id, | |
187 | connector->name, | |
188 | drm_get_connector_status_name(old_status), | |
189 | drm_get_connector_status_name(connector->status)); | |
190 | ||
191 | return true; | |
192 | } | |
193 | ||
194 | static void i915_digport_work_func(struct work_struct *work) | |
195 | { | |
196 | struct drm_i915_private *dev_priv = | |
197 | container_of(work, struct drm_i915_private, hotplug.dig_port_work); | |
198 | u32 long_port_mask, short_port_mask; | |
199 | struct intel_digital_port *intel_dig_port; | |
200 | int i; | |
201 | u32 old_bits = 0; | |
202 | ||
203 | spin_lock_irq(&dev_priv->irq_lock); | |
204 | long_port_mask = dev_priv->hotplug.long_port_mask; | |
205 | dev_priv->hotplug.long_port_mask = 0; | |
206 | short_port_mask = dev_priv->hotplug.short_port_mask; | |
207 | dev_priv->hotplug.short_port_mask = 0; | |
208 | spin_unlock_irq(&dev_priv->irq_lock); | |
209 | ||
210 | for (i = 0; i < I915_MAX_PORTS; i++) { | |
211 | bool valid = false; | |
212 | bool long_hpd = false; | |
213 | intel_dig_port = dev_priv->hotplug.irq_port[i]; | |
214 | if (!intel_dig_port || !intel_dig_port->hpd_pulse) | |
215 | continue; | |
216 | ||
217 | if (long_port_mask & (1 << i)) { | |
218 | valid = true; | |
219 | long_hpd = true; | |
220 | } else if (short_port_mask & (1 << i)) | |
221 | valid = true; | |
222 | ||
223 | if (valid) { | |
224 | enum irqreturn ret; | |
225 | ||
226 | ret = intel_dig_port->hpd_pulse(intel_dig_port, long_hpd); | |
227 | if (ret == IRQ_NONE) { | |
228 | /* fall back to old school hpd */ | |
229 | old_bits |= (1 << intel_dig_port->base.hpd_pin); | |
230 | } | |
231 | } | |
232 | } | |
233 | ||
234 | if (old_bits) { | |
235 | spin_lock_irq(&dev_priv->irq_lock); | |
236 | dev_priv->hotplug.event_bits |= old_bits; | |
237 | spin_unlock_irq(&dev_priv->irq_lock); | |
238 | schedule_work(&dev_priv->hotplug.hotplug_work); | |
239 | } | |
240 | } | |
241 | ||
242 | /* | |
243 | * Handle hotplug events outside the interrupt handler proper. | |
244 | */ | |
245 | static void i915_hotplug_work_func(struct work_struct *work) | |
246 | { | |
247 | struct drm_i915_private *dev_priv = | |
248 | container_of(work, struct drm_i915_private, hotplug.hotplug_work); | |
249 | struct drm_device *dev = dev_priv->dev; | |
250 | struct drm_mode_config *mode_config = &dev->mode_config; | |
251 | struct intel_connector *intel_connector; | |
252 | struct intel_encoder *intel_encoder; | |
253 | struct drm_connector *connector; | |
254 | bool changed = false; | |
255 | u32 hpd_event_bits; | |
256 | ||
257 | mutex_lock(&mode_config->mutex); | |
258 | DRM_DEBUG_KMS("running encoder hotplug functions\n"); | |
259 | ||
260 | spin_lock_irq(&dev_priv->irq_lock); | |
261 | ||
262 | hpd_event_bits = dev_priv->hotplug.event_bits; | |
263 | dev_priv->hotplug.event_bits = 0; | |
264 | ||
265 | /* Disable hotplug on connectors that hit an irq storm. */ | |
266 | intel_hpd_irq_storm_disable(dev_priv); | |
267 | ||
268 | spin_unlock_irq(&dev_priv->irq_lock); | |
269 | ||
270 | list_for_each_entry(connector, &mode_config->connector_list, head) { | |
271 | intel_connector = to_intel_connector(connector); | |
272 | if (!intel_connector->encoder) | |
273 | continue; | |
274 | intel_encoder = intel_connector->encoder; | |
275 | if (hpd_event_bits & (1 << intel_encoder->hpd_pin)) { | |
276 | DRM_DEBUG_KMS("Connector %s (pin %i) received hotplug event.\n", | |
277 | connector->name, intel_encoder->hpd_pin); | |
278 | if (intel_encoder->hot_plug) | |
279 | intel_encoder->hot_plug(intel_encoder); | |
280 | if (intel_hpd_irq_event(dev, connector)) | |
281 | changed = true; | |
282 | } | |
283 | } | |
284 | mutex_unlock(&mode_config->mutex); | |
285 | ||
286 | if (changed) | |
287 | drm_kms_helper_hotplug_event(dev); | |
288 | } | |
289 | ||
290 | ||
291 | /** | |
292 | * intel_hpd_irq_handler - main hotplug irq handler | |
293 | * @dev: drm device | |
294 | * @pin_mask: a mask of hpd pins that have triggered the irq | |
295 | * @long_mask: a mask of hpd pins that may be long hpd pulses | |
296 | * | |
297 | * This is the main hotplug irq handler for all platforms. The platform specific | |
298 | * irq handlers call the platform specific hotplug irq handlers, which read and | |
299 | * decode the appropriate registers into bitmasks about hpd pins that have | |
300 | * triggered (@pin_mask), and which of those pins may be long pulses | |
301 | * (@long_mask). The @long_mask is ignored if the port corresponding to the pin | |
302 | * is not a digital port. | |
303 | * | |
304 | * Here, we do hotplug irq storm detection and mitigation, and pass further | |
305 | * processing to appropriate bottom halves. | |
306 | */ | |
307 | void intel_hpd_irq_handler(struct drm_device *dev, | |
308 | u32 pin_mask, u32 long_mask) | |
309 | { | |
310 | struct drm_i915_private *dev_priv = dev->dev_private; | |
311 | int i; | |
312 | enum port port; | |
313 | bool storm_detected = false; | |
314 | bool queue_dig = false, queue_hp = false; | |
315 | bool is_dig_port; | |
316 | ||
317 | if (!pin_mask) | |
318 | return; | |
319 | ||
320 | spin_lock(&dev_priv->irq_lock); | |
321 | for_each_hpd_pin(i) { | |
322 | if (!(BIT(i) & pin_mask)) | |
323 | continue; | |
324 | ||
325 | port = intel_hpd_pin_to_port(i); | |
326 | is_dig_port = port && dev_priv->hotplug.irq_port[port]; | |
327 | ||
328 | if (is_dig_port) { | |
329 | bool long_hpd = long_mask & BIT(i); | |
330 | ||
331 | DRM_DEBUG_DRIVER("digital hpd port %c - %s\n", port_name(port), | |
332 | long_hpd ? "long" : "short"); | |
333 | /* | |
334 | * For long HPD pulses we want to have the digital queue happen, | |
335 | * but we still want HPD storm detection to function. | |
336 | */ | |
337 | queue_dig = true; | |
338 | if (long_hpd) { | |
339 | dev_priv->hotplug.long_port_mask |= (1 << port); | |
340 | } else { | |
341 | /* for short HPD just trigger the digital queue */ | |
342 | dev_priv->hotplug.short_port_mask |= (1 << port); | |
343 | continue; | |
344 | } | |
345 | } | |
346 | ||
347 | if (dev_priv->hotplug.stats[i].state == HPD_DISABLED) { | |
348 | /* | |
349 | * On GMCH platforms the interrupt mask bits only | |
350 | * prevent irq generation, not the setting of the | |
351 | * hotplug bits itself. So only WARN about unexpected | |
352 | * interrupts on saner platforms. | |
353 | */ | |
354 | WARN_ONCE(INTEL_INFO(dev)->gen >= 5 && !IS_VALLEYVIEW(dev), | |
355 | "Received HPD interrupt on pin %d although disabled\n", i); | |
356 | continue; | |
357 | } | |
358 | ||
359 | if (dev_priv->hotplug.stats[i].state != HPD_ENABLED) | |
360 | continue; | |
361 | ||
362 | if (!is_dig_port) { | |
363 | dev_priv->hotplug.event_bits |= BIT(i); | |
364 | queue_hp = true; | |
365 | } | |
366 | ||
367 | if (intel_hpd_irq_storm_detect(dev_priv, i)) { | |
368 | dev_priv->hotplug.event_bits &= ~BIT(i); | |
369 | storm_detected = true; | |
370 | } | |
371 | } | |
372 | ||
373 | if (storm_detected) | |
374 | dev_priv->display.hpd_irq_setup(dev); | |
375 | spin_unlock(&dev_priv->irq_lock); | |
376 | ||
377 | /* | |
378 | * Our hotplug handler can grab modeset locks (by calling down into the | |
379 | * fb helpers). Hence it must not be run on our own dev-priv->wq work | |
380 | * queue for otherwise the flush_work in the pageflip code will | |
381 | * deadlock. | |
382 | */ | |
383 | if (queue_dig) | |
384 | queue_work(dev_priv->hotplug.dp_wq, &dev_priv->hotplug.dig_port_work); | |
385 | if (queue_hp) | |
386 | schedule_work(&dev_priv->hotplug.hotplug_work); | |
387 | } | |
388 | ||
389 | /** | |
390 | * intel_hpd_init - initializes and enables hpd support | |
391 | * @dev_priv: i915 device instance | |
392 | * | |
393 | * This function enables the hotplug support. It requires that interrupts have | |
394 | * already been enabled with intel_irq_init_hw(). From this point on hotplug and | |
395 | * poll request can run concurrently to other code, so locking rules must be | |
396 | * obeyed. | |
397 | * | |
398 | * This is a separate step from interrupt enabling to simplify the locking rules | |
399 | * in the driver load and resume code. | |
400 | */ | |
401 | void intel_hpd_init(struct drm_i915_private *dev_priv) | |
402 | { | |
403 | struct drm_device *dev = dev_priv->dev; | |
404 | struct drm_mode_config *mode_config = &dev->mode_config; | |
405 | struct drm_connector *connector; | |
406 | int i; | |
407 | ||
408 | for_each_hpd_pin(i) { | |
409 | dev_priv->hotplug.stats[i].count = 0; | |
410 | dev_priv->hotplug.stats[i].state = HPD_ENABLED; | |
411 | } | |
412 | list_for_each_entry(connector, &mode_config->connector_list, head) { | |
413 | struct intel_connector *intel_connector = to_intel_connector(connector); | |
414 | connector->polled = intel_connector->polled; | |
415 | if (connector->encoder && !connector->polled && I915_HAS_HOTPLUG(dev) && intel_connector->encoder->hpd_pin > HPD_NONE) | |
416 | connector->polled = DRM_CONNECTOR_POLL_HPD; | |
417 | if (intel_connector->mst_port) | |
418 | connector->polled = DRM_CONNECTOR_POLL_HPD; | |
419 | } | |
420 | ||
421 | /* | |
422 | * Interrupt setup is already guaranteed to be single-threaded, this is | |
423 | * just to make the assert_spin_locked checks happy. | |
424 | */ | |
425 | spin_lock_irq(&dev_priv->irq_lock); | |
426 | if (dev_priv->display.hpd_irq_setup) | |
427 | dev_priv->display.hpd_irq_setup(dev); | |
428 | spin_unlock_irq(&dev_priv->irq_lock); | |
429 | } | |
430 | ||
431 | void intel_hpd_init_work(struct drm_i915_private *dev_priv) | |
432 | { | |
433 | INIT_WORK(&dev_priv->hotplug.hotplug_work, i915_hotplug_work_func); | |
434 | INIT_WORK(&dev_priv->hotplug.dig_port_work, i915_digport_work_func); | |
435 | INIT_DELAYED_WORK(&dev_priv->hotplug.reenable_work, | |
436 | intel_hpd_irq_storm_reenable_work); | |
437 | } | |
438 | ||
439 | void intel_hpd_cancel_work(struct drm_i915_private *dev_priv) | |
440 | { | |
441 | spin_lock_irq(&dev_priv->irq_lock); | |
442 | ||
443 | dev_priv->hotplug.long_port_mask = 0; | |
444 | dev_priv->hotplug.short_port_mask = 0; | |
445 | dev_priv->hotplug.event_bits = 0; | |
446 | ||
447 | spin_unlock_irq(&dev_priv->irq_lock); | |
448 | ||
449 | cancel_work_sync(&dev_priv->hotplug.dig_port_work); | |
450 | cancel_work_sync(&dev_priv->hotplug.hotplug_work); | |
451 | cancel_delayed_work_sync(&dev_priv->hotplug.reenable_work); | |
452 | } |