xref: /linux/drivers/gpu/drm/i915/display/intel_crtc.c (revision d642ef71)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2020 Intel Corporation
4  */
5 #include <linux/kernel.h>
6 #include <linux/pm_qos.h>
7 #include <linux/slab.h>
8 
9 #include <drm/drm_atomic_helper.h>
10 #include <drm/drm_fourcc.h>
11 #include <drm/drm_plane.h>
12 #include <drm/drm_vblank_work.h>
13 
14 #include "i915_vgpu.h"
15 #include "i9xx_plane.h"
16 #include "icl_dsi.h"
17 #include "intel_atomic.h"
18 #include "intel_atomic_plane.h"
19 #include "intel_color.h"
20 #include "intel_crtc.h"
21 #include "intel_cursor.h"
22 #include "intel_display_debugfs.h"
23 #include "intel_display_irq.h"
24 #include "intel_display_trace.h"
25 #include "intel_display_types.h"
26 #include "intel_drrs.h"
27 #include "intel_dsb.h"
28 #include "intel_dsi.h"
29 #include "intel_fifo_underrun.h"
30 #include "intel_pipe_crc.h"
31 #include "intel_psr.h"
32 #include "intel_sprite.h"
33 #include "intel_vblank.h"
34 #include "intel_vrr.h"
35 #include "skl_universal_plane.h"
36 
37 static void assert_vblank_disabled(struct drm_crtc *crtc)
38 {
39 	struct drm_i915_private *i915 = to_i915(crtc->dev);
40 
41 	if (I915_STATE_WARN(i915, drm_crtc_vblank_get(crtc) == 0,
42 			    "[CRTC:%d:%s] vblank assertion failure (expected off, current on)\n",
43 			    crtc->base.id, crtc->name))
44 		drm_crtc_vblank_put(crtc);
45 }
46 
47 struct intel_crtc *intel_first_crtc(struct drm_i915_private *i915)
48 {
49 	return to_intel_crtc(drm_crtc_from_index(&i915->drm, 0));
50 }
51 
52 struct intel_crtc *intel_crtc_for_pipe(struct drm_i915_private *i915,
53 				       enum pipe pipe)
54 {
55 	struct intel_crtc *crtc;
56 
57 	for_each_intel_crtc(&i915->drm, crtc) {
58 		if (crtc->pipe == pipe)
59 			return crtc;
60 	}
61 
62 	return NULL;
63 }
64 
65 void intel_crtc_wait_for_next_vblank(struct intel_crtc *crtc)
66 {
67 	drm_crtc_wait_one_vblank(&crtc->base);
68 }
69 
70 void intel_wait_for_vblank_if_active(struct drm_i915_private *i915,
71 				     enum pipe pipe)
72 {
73 	struct intel_crtc *crtc = intel_crtc_for_pipe(i915, pipe);
74 
75 	if (crtc->active)
76 		intel_crtc_wait_for_next_vblank(crtc);
77 }
78 
79 u32 intel_crtc_get_vblank_counter(struct intel_crtc *crtc)
80 {
81 	struct drm_device *dev = crtc->base.dev;
82 	struct drm_vblank_crtc *vblank = &dev->vblank[drm_crtc_index(&crtc->base)];
83 
84 	if (!crtc->active)
85 		return 0;
86 
87 	if (!vblank->max_vblank_count)
88 		return (u32)drm_crtc_accurate_vblank_count(&crtc->base);
89 
90 	return crtc->base.funcs->get_vblank_counter(&crtc->base);
91 }
92 
93 u32 intel_crtc_max_vblank_count(const struct intel_crtc_state *crtc_state)
94 {
95 	struct drm_i915_private *dev_priv = to_i915(crtc_state->uapi.crtc->dev);
96 
97 	/*
98 	 * From Gen 11, In case of dsi cmd mode, frame counter wouldnt
99 	 * have updated at the beginning of TE, if we want to use
100 	 * the hw counter, then we would find it updated in only
101 	 * the next TE, hence switching to sw counter.
102 	 */
103 	if (crtc_state->mode_flags & (I915_MODE_FLAG_DSI_USE_TE0 |
104 				      I915_MODE_FLAG_DSI_USE_TE1))
105 		return 0;
106 
107 	/*
108 	 * On i965gm the hardware frame counter reads
109 	 * zero when the TV encoder is enabled :(
110 	 */
111 	if (IS_I965GM(dev_priv) &&
112 	    (crtc_state->output_types & BIT(INTEL_OUTPUT_TVOUT)))
113 		return 0;
114 
115 	if (DISPLAY_VER(dev_priv) >= 5 || IS_G4X(dev_priv))
116 		return 0xffffffff; /* full 32 bit counter */
117 	else if (DISPLAY_VER(dev_priv) >= 3)
118 		return 0xffffff; /* only 24 bits of frame count */
119 	else
120 		return 0; /* Gen2 doesn't have a hardware frame counter */
121 }
122 
123 void intel_crtc_vblank_on(const struct intel_crtc_state *crtc_state)
124 {
125 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
126 
127 	assert_vblank_disabled(&crtc->base);
128 	drm_crtc_set_max_vblank_count(&crtc->base,
129 				      intel_crtc_max_vblank_count(crtc_state));
130 	drm_crtc_vblank_on(&crtc->base);
131 
132 	/*
133 	 * Should really happen exactly when we enable the pipe
134 	 * but we want the frame counters in the trace, and that
135 	 * requires vblank support on some platforms/outputs.
136 	 */
137 	trace_intel_pipe_enable(crtc);
138 }
139 
140 void intel_crtc_vblank_off(const struct intel_crtc_state *crtc_state)
141 {
142 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
143 
144 	/*
145 	 * Should really happen exactly when we disable the pipe
146 	 * but we want the frame counters in the trace, and that
147 	 * requires vblank support on some platforms/outputs.
148 	 */
149 	trace_intel_pipe_disable(crtc);
150 
151 	drm_crtc_vblank_off(&crtc->base);
152 	assert_vblank_disabled(&crtc->base);
153 }
154 
155 struct intel_crtc_state *intel_crtc_state_alloc(struct intel_crtc *crtc)
156 {
157 	struct intel_crtc_state *crtc_state;
158 
159 	crtc_state = kmalloc(sizeof(*crtc_state), GFP_KERNEL);
160 
161 	if (crtc_state)
162 		intel_crtc_state_reset(crtc_state, crtc);
163 
164 	return crtc_state;
165 }
166 
167 void intel_crtc_state_reset(struct intel_crtc_state *crtc_state,
168 			    struct intel_crtc *crtc)
169 {
170 	memset(crtc_state, 0, sizeof(*crtc_state));
171 
172 	__drm_atomic_helper_crtc_state_reset(&crtc_state->uapi, &crtc->base);
173 
174 	crtc_state->cpu_transcoder = INVALID_TRANSCODER;
175 	crtc_state->master_transcoder = INVALID_TRANSCODER;
176 	crtc_state->hsw_workaround_pipe = INVALID_PIPE;
177 	crtc_state->scaler_state.scaler_id = -1;
178 	crtc_state->mst_master_transcoder = INVALID_TRANSCODER;
179 	crtc_state->max_link_bpp_x16 = INT_MAX;
180 }
181 
182 static struct intel_crtc *intel_crtc_alloc(void)
183 {
184 	struct intel_crtc_state *crtc_state;
185 	struct intel_crtc *crtc;
186 
187 	crtc = kzalloc(sizeof(*crtc), GFP_KERNEL);
188 	if (!crtc)
189 		return ERR_PTR(-ENOMEM);
190 
191 	crtc_state = intel_crtc_state_alloc(crtc);
192 	if (!crtc_state) {
193 		kfree(crtc);
194 		return ERR_PTR(-ENOMEM);
195 	}
196 
197 	crtc->base.state = &crtc_state->uapi;
198 	crtc->config = crtc_state;
199 
200 	return crtc;
201 }
202 
203 static void intel_crtc_free(struct intel_crtc *crtc)
204 {
205 	intel_crtc_destroy_state(&crtc->base, crtc->base.state);
206 	kfree(crtc);
207 }
208 
209 static void intel_crtc_destroy(struct drm_crtc *_crtc)
210 {
211 	struct intel_crtc *crtc = to_intel_crtc(_crtc);
212 
213 	cpu_latency_qos_remove_request(&crtc->vblank_pm_qos);
214 
215 	drm_crtc_cleanup(&crtc->base);
216 	kfree(crtc);
217 }
218 
219 static int intel_crtc_late_register(struct drm_crtc *crtc)
220 {
221 	intel_crtc_debugfs_add(to_intel_crtc(crtc));
222 	return 0;
223 }
224 
225 #define INTEL_CRTC_FUNCS \
226 	.set_config = drm_atomic_helper_set_config, \
227 	.destroy = intel_crtc_destroy, \
228 	.page_flip = drm_atomic_helper_page_flip, \
229 	.atomic_duplicate_state = intel_crtc_duplicate_state, \
230 	.atomic_destroy_state = intel_crtc_destroy_state, \
231 	.set_crc_source = intel_crtc_set_crc_source, \
232 	.verify_crc_source = intel_crtc_verify_crc_source, \
233 	.get_crc_sources = intel_crtc_get_crc_sources, \
234 	.late_register = intel_crtc_late_register
235 
236 static const struct drm_crtc_funcs bdw_crtc_funcs = {
237 	INTEL_CRTC_FUNCS,
238 
239 	.get_vblank_counter = g4x_get_vblank_counter,
240 	.enable_vblank = bdw_enable_vblank,
241 	.disable_vblank = bdw_disable_vblank,
242 	.get_vblank_timestamp = intel_crtc_get_vblank_timestamp,
243 };
244 
245 static const struct drm_crtc_funcs ilk_crtc_funcs = {
246 	INTEL_CRTC_FUNCS,
247 
248 	.get_vblank_counter = g4x_get_vblank_counter,
249 	.enable_vblank = ilk_enable_vblank,
250 	.disable_vblank = ilk_disable_vblank,
251 	.get_vblank_timestamp = intel_crtc_get_vblank_timestamp,
252 };
253 
254 static const struct drm_crtc_funcs g4x_crtc_funcs = {
255 	INTEL_CRTC_FUNCS,
256 
257 	.get_vblank_counter = g4x_get_vblank_counter,
258 	.enable_vblank = i965_enable_vblank,
259 	.disable_vblank = i965_disable_vblank,
260 	.get_vblank_timestamp = intel_crtc_get_vblank_timestamp,
261 };
262 
263 static const struct drm_crtc_funcs i965_crtc_funcs = {
264 	INTEL_CRTC_FUNCS,
265 
266 	.get_vblank_counter = i915_get_vblank_counter,
267 	.enable_vblank = i965_enable_vblank,
268 	.disable_vblank = i965_disable_vblank,
269 	.get_vblank_timestamp = intel_crtc_get_vblank_timestamp,
270 };
271 
272 static const struct drm_crtc_funcs i915gm_crtc_funcs = {
273 	INTEL_CRTC_FUNCS,
274 
275 	.get_vblank_counter = i915_get_vblank_counter,
276 	.enable_vblank = i915gm_enable_vblank,
277 	.disable_vblank = i915gm_disable_vblank,
278 	.get_vblank_timestamp = intel_crtc_get_vblank_timestamp,
279 };
280 
281 static const struct drm_crtc_funcs i915_crtc_funcs = {
282 	INTEL_CRTC_FUNCS,
283 
284 	.get_vblank_counter = i915_get_vblank_counter,
285 	.enable_vblank = i8xx_enable_vblank,
286 	.disable_vblank = i8xx_disable_vblank,
287 	.get_vblank_timestamp = intel_crtc_get_vblank_timestamp,
288 };
289 
290 static const struct drm_crtc_funcs i8xx_crtc_funcs = {
291 	INTEL_CRTC_FUNCS,
292 
293 	/* no hw vblank counter */
294 	.enable_vblank = i8xx_enable_vblank,
295 	.disable_vblank = i8xx_disable_vblank,
296 	.get_vblank_timestamp = intel_crtc_get_vblank_timestamp,
297 };
298 
299 int intel_crtc_init(struct drm_i915_private *dev_priv, enum pipe pipe)
300 {
301 	struct intel_plane *primary, *cursor;
302 	const struct drm_crtc_funcs *funcs;
303 	struct intel_crtc *crtc;
304 	int sprite, ret;
305 
306 	crtc = intel_crtc_alloc();
307 	if (IS_ERR(crtc))
308 		return PTR_ERR(crtc);
309 
310 	crtc->pipe = pipe;
311 	crtc->num_scalers = DISPLAY_RUNTIME_INFO(dev_priv)->num_scalers[pipe];
312 
313 	if (DISPLAY_VER(dev_priv) >= 9)
314 		primary = skl_universal_plane_create(dev_priv, pipe,
315 						     PLANE_PRIMARY);
316 	else
317 		primary = intel_primary_plane_create(dev_priv, pipe);
318 	if (IS_ERR(primary)) {
319 		ret = PTR_ERR(primary);
320 		goto fail;
321 	}
322 	crtc->plane_ids_mask |= BIT(primary->id);
323 
324 	intel_init_fifo_underrun_reporting(dev_priv, crtc, false);
325 
326 	for_each_sprite(dev_priv, pipe, sprite) {
327 		struct intel_plane *plane;
328 
329 		if (DISPLAY_VER(dev_priv) >= 9)
330 			plane = skl_universal_plane_create(dev_priv, pipe,
331 							   PLANE_SPRITE0 + sprite);
332 		else
333 			plane = intel_sprite_plane_create(dev_priv, pipe, sprite);
334 		if (IS_ERR(plane)) {
335 			ret = PTR_ERR(plane);
336 			goto fail;
337 		}
338 		crtc->plane_ids_mask |= BIT(plane->id);
339 	}
340 
341 	cursor = intel_cursor_plane_create(dev_priv, pipe);
342 	if (IS_ERR(cursor)) {
343 		ret = PTR_ERR(cursor);
344 		goto fail;
345 	}
346 	crtc->plane_ids_mask |= BIT(cursor->id);
347 
348 	if (HAS_GMCH(dev_priv)) {
349 		if (IS_CHERRYVIEW(dev_priv) ||
350 		    IS_VALLEYVIEW(dev_priv) || IS_G4X(dev_priv))
351 			funcs = &g4x_crtc_funcs;
352 		else if (DISPLAY_VER(dev_priv) == 4)
353 			funcs = &i965_crtc_funcs;
354 		else if (IS_I945GM(dev_priv) || IS_I915GM(dev_priv))
355 			funcs = &i915gm_crtc_funcs;
356 		else if (DISPLAY_VER(dev_priv) == 3)
357 			funcs = &i915_crtc_funcs;
358 		else
359 			funcs = &i8xx_crtc_funcs;
360 	} else {
361 		if (DISPLAY_VER(dev_priv) >= 8)
362 			funcs = &bdw_crtc_funcs;
363 		else
364 			funcs = &ilk_crtc_funcs;
365 	}
366 
367 	ret = drm_crtc_init_with_planes(&dev_priv->drm, &crtc->base,
368 					&primary->base, &cursor->base,
369 					funcs, "pipe %c", pipe_name(pipe));
370 	if (ret)
371 		goto fail;
372 
373 	if (DISPLAY_VER(dev_priv) >= 11)
374 		drm_crtc_create_scaling_filter_property(&crtc->base,
375 						BIT(DRM_SCALING_FILTER_DEFAULT) |
376 						BIT(DRM_SCALING_FILTER_NEAREST_NEIGHBOR));
377 
378 	intel_color_crtc_init(crtc);
379 	intel_drrs_crtc_init(crtc);
380 	intel_crtc_crc_init(crtc);
381 
382 	cpu_latency_qos_add_request(&crtc->vblank_pm_qos, PM_QOS_DEFAULT_VALUE);
383 
384 	drm_WARN_ON(&dev_priv->drm, drm_crtc_index(&crtc->base) != crtc->pipe);
385 
386 	return 0;
387 
388 fail:
389 	intel_crtc_free(crtc);
390 
391 	return ret;
392 }
393 
394 static bool intel_crtc_needs_vblank_work(const struct intel_crtc_state *crtc_state)
395 {
396 	return crtc_state->hw.active &&
397 		!intel_crtc_needs_modeset(crtc_state) &&
398 		!crtc_state->preload_luts &&
399 		intel_crtc_needs_color_update(crtc_state) &&
400 		!intel_color_uses_dsb(crtc_state);
401 }
402 
403 static void intel_crtc_vblank_work(struct kthread_work *base)
404 {
405 	struct drm_vblank_work *work = to_drm_vblank_work(base);
406 	struct intel_crtc_state *crtc_state =
407 		container_of(work, typeof(*crtc_state), vblank_work);
408 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
409 
410 	trace_intel_crtc_vblank_work_start(crtc);
411 
412 	intel_color_load_luts(crtc_state);
413 
414 	if (crtc_state->uapi.event) {
415 		spin_lock_irq(&crtc->base.dev->event_lock);
416 		drm_crtc_send_vblank_event(&crtc->base, crtc_state->uapi.event);
417 		crtc_state->uapi.event = NULL;
418 		spin_unlock_irq(&crtc->base.dev->event_lock);
419 	}
420 
421 	trace_intel_crtc_vblank_work_end(crtc);
422 }
423 
424 static void intel_crtc_vblank_work_init(struct intel_crtc_state *crtc_state)
425 {
426 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
427 
428 	drm_vblank_work_init(&crtc_state->vblank_work, &crtc->base,
429 			     intel_crtc_vblank_work);
430 	/*
431 	 * Interrupt latency is critical for getting the vblank
432 	 * work executed as early as possible during the vblank.
433 	 */
434 	cpu_latency_qos_update_request(&crtc->vblank_pm_qos, 0);
435 }
436 
437 void intel_wait_for_vblank_workers(struct intel_atomic_state *state)
438 {
439 	struct intel_crtc_state *crtc_state;
440 	struct intel_crtc *crtc;
441 	int i;
442 
443 	for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i) {
444 		if (!intel_crtc_needs_vblank_work(crtc_state))
445 			continue;
446 
447 		drm_vblank_work_flush(&crtc_state->vblank_work);
448 		cpu_latency_qos_update_request(&crtc->vblank_pm_qos,
449 					       PM_QOS_DEFAULT_VALUE);
450 	}
451 }
452 
453 int intel_usecs_to_scanlines(const struct drm_display_mode *adjusted_mode,
454 			     int usecs)
455 {
456 	/* paranoia */
457 	if (!adjusted_mode->crtc_htotal)
458 		return 1;
459 
460 	return DIV_ROUND_UP(usecs * adjusted_mode->crtc_clock,
461 			    1000 * adjusted_mode->crtc_htotal);
462 }
463 
464 static int intel_mode_vblank_start(const struct drm_display_mode *mode)
465 {
466 	int vblank_start = mode->crtc_vblank_start;
467 
468 	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
469 		vblank_start = DIV_ROUND_UP(vblank_start, 2);
470 
471 	return vblank_start;
472 }
473 
474 static void intel_crtc_vblank_evade_scanlines(struct intel_atomic_state *state,
475 					      struct intel_crtc *crtc,
476 					      int *min, int *max, int *vblank_start)
477 {
478 	const struct intel_crtc_state *old_crtc_state =
479 		intel_atomic_get_old_crtc_state(state, crtc);
480 	const struct intel_crtc_state *new_crtc_state =
481 		intel_atomic_get_new_crtc_state(state, crtc);
482 	const struct intel_crtc_state *crtc_state;
483 	const struct drm_display_mode *adjusted_mode;
484 
485 	/*
486 	 * During fastsets/etc. the transcoder is still
487 	 * running with the old timings at this point.
488 	 *
489 	 * TODO: maybe just use the active timings here?
490 	 */
491 	if (intel_crtc_needs_modeset(new_crtc_state))
492 		crtc_state = new_crtc_state;
493 	else
494 		crtc_state = old_crtc_state;
495 
496 	adjusted_mode = &crtc_state->hw.adjusted_mode;
497 
498 	if (crtc->mode_flags & I915_MODE_FLAG_VRR) {
499 		/* timing changes should happen with VRR disabled */
500 		drm_WARN_ON(state->base.dev, intel_crtc_needs_modeset(new_crtc_state) ||
501 			    new_crtc_state->update_m_n || new_crtc_state->update_lrr);
502 
503 		if (intel_vrr_is_push_sent(crtc_state))
504 			*vblank_start = intel_vrr_vmin_vblank_start(crtc_state);
505 		else
506 			*vblank_start = intel_vrr_vmax_vblank_start(crtc_state);
507 	} else {
508 		*vblank_start = intel_mode_vblank_start(adjusted_mode);
509 	}
510 
511 	/* FIXME needs to be calibrated sensibly */
512 	*min = *vblank_start - intel_usecs_to_scanlines(adjusted_mode,
513 							VBLANK_EVASION_TIME_US);
514 	*max = *vblank_start - 1;
515 
516 	/*
517 	 * M/N and TRANS_VTOTAL are double buffered on the transcoder's
518 	 * undelayed vblank, so with seamless M/N and LRR we must evade
519 	 * both vblanks.
520 	 *
521 	 * DSB execution waits for the transcoder's undelayed vblank,
522 	 * hence we must kick off the commit before that.
523 	 */
524 	if (new_crtc_state->dsb || new_crtc_state->update_m_n || new_crtc_state->update_lrr)
525 		*min -= adjusted_mode->crtc_vblank_start - adjusted_mode->crtc_vdisplay;
526 }
527 
528 /**
529  * intel_pipe_update_start() - start update of a set of display registers
530  * @state: the atomic state
531  * @crtc: the crtc
532  *
533  * Mark the start of an update to pipe registers that should be updated
534  * atomically regarding vblank. If the next vblank will happens within
535  * the next 100 us, this function waits until the vblank passes.
536  *
537  * After a successful call to this function, interrupts will be disabled
538  * until a subsequent call to intel_pipe_update_end(). That is done to
539  * avoid random delays.
540  */
541 void intel_pipe_update_start(struct intel_atomic_state *state,
542 			     struct intel_crtc *crtc)
543 {
544 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
545 	struct intel_crtc_state *new_crtc_state =
546 		intel_atomic_get_new_crtc_state(state, crtc);
547 	long timeout = msecs_to_jiffies_timeout(1);
548 	int scanline, min, max, vblank_start;
549 	wait_queue_head_t *wq = drm_crtc_vblank_waitqueue(&crtc->base);
550 	bool need_vlv_dsi_wa = (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) &&
551 		intel_crtc_has_type(new_crtc_state, INTEL_OUTPUT_DSI);
552 	DEFINE_WAIT(wait);
553 
554 	intel_psr_lock(new_crtc_state);
555 
556 	if (new_crtc_state->do_async_flip)
557 		return;
558 
559 	if (intel_crtc_needs_vblank_work(new_crtc_state))
560 		intel_crtc_vblank_work_init(new_crtc_state);
561 
562 	intel_crtc_vblank_evade_scanlines(state, crtc, &min, &max, &vblank_start);
563 	if (min <= 0 || max <= 0)
564 		goto irq_disable;
565 
566 	if (drm_WARN_ON(&dev_priv->drm, drm_crtc_vblank_get(&crtc->base)))
567 		goto irq_disable;
568 
569 	/*
570 	 * Wait for psr to idle out after enabling the VBL interrupts
571 	 * VBL interrupts will start the PSR exit and prevent a PSR
572 	 * re-entry as well.
573 	 */
574 	intel_psr_wait_for_idle_locked(new_crtc_state);
575 
576 	local_irq_disable();
577 
578 	crtc->debug.min_vbl = min;
579 	crtc->debug.max_vbl = max;
580 	trace_intel_pipe_update_start(crtc);
581 
582 	for (;;) {
583 		/*
584 		 * prepare_to_wait() has a memory barrier, which guarantees
585 		 * other CPUs can see the task state update by the time we
586 		 * read the scanline.
587 		 */
588 		prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE);
589 
590 		scanline = intel_get_crtc_scanline(crtc);
591 		if (scanline < min || scanline > max)
592 			break;
593 
594 		if (!timeout) {
595 			drm_err(&dev_priv->drm,
596 				"Potential atomic update failure on pipe %c\n",
597 				pipe_name(crtc->pipe));
598 			break;
599 		}
600 
601 		local_irq_enable();
602 
603 		timeout = schedule_timeout(timeout);
604 
605 		local_irq_disable();
606 	}
607 
608 	finish_wait(wq, &wait);
609 
610 	drm_crtc_vblank_put(&crtc->base);
611 
612 	/*
613 	 * On VLV/CHV DSI the scanline counter would appear to
614 	 * increment approx. 1/3 of a scanline before start of vblank.
615 	 * The registers still get latched at start of vblank however.
616 	 * This means we must not write any registers on the first
617 	 * line of vblank (since not the whole line is actually in
618 	 * vblank). And unfortunately we can't use the interrupt to
619 	 * wait here since it will fire too soon. We could use the
620 	 * frame start interrupt instead since it will fire after the
621 	 * critical scanline, but that would require more changes
622 	 * in the interrupt code. So for now we'll just do the nasty
623 	 * thing and poll for the bad scanline to pass us by.
624 	 *
625 	 * FIXME figure out if BXT+ DSI suffers from this as well
626 	 */
627 	while (need_vlv_dsi_wa && scanline == vblank_start)
628 		scanline = intel_get_crtc_scanline(crtc);
629 
630 	crtc->debug.scanline_start = scanline;
631 	crtc->debug.start_vbl_time = ktime_get();
632 	crtc->debug.start_vbl_count = intel_crtc_get_vblank_counter(crtc);
633 
634 	trace_intel_pipe_update_vblank_evaded(crtc);
635 	return;
636 
637 irq_disable:
638 	local_irq_disable();
639 }
640 
641 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_VBLANK_EVADE)
642 static void dbg_vblank_evade(struct intel_crtc *crtc, ktime_t end)
643 {
644 	u64 delta = ktime_to_ns(ktime_sub(end, crtc->debug.start_vbl_time));
645 	unsigned int h;
646 
647 	h = ilog2(delta >> 9);
648 	if (h >= ARRAY_SIZE(crtc->debug.vbl.times))
649 		h = ARRAY_SIZE(crtc->debug.vbl.times) - 1;
650 	crtc->debug.vbl.times[h]++;
651 
652 	crtc->debug.vbl.sum += delta;
653 	if (!crtc->debug.vbl.min || delta < crtc->debug.vbl.min)
654 		crtc->debug.vbl.min = delta;
655 	if (delta > crtc->debug.vbl.max)
656 		crtc->debug.vbl.max = delta;
657 
658 	if (delta > 1000 * VBLANK_EVASION_TIME_US) {
659 		drm_dbg_kms(crtc->base.dev,
660 			    "Atomic update on pipe (%c) took %lld us, max time under evasion is %u us\n",
661 			    pipe_name(crtc->pipe),
662 			    div_u64(delta, 1000),
663 			    VBLANK_EVASION_TIME_US);
664 		crtc->debug.vbl.over++;
665 	}
666 }
667 #else
668 static void dbg_vblank_evade(struct intel_crtc *crtc, ktime_t end) {}
669 #endif
670 
671 /**
672  * intel_pipe_update_end() - end update of a set of display registers
673  * @state: the atomic state
674  * @crtc: the crtc
675  *
676  * Mark the end of an update started with intel_pipe_update_start(). This
677  * re-enables interrupts and verifies the update was actually completed
678  * before a vblank.
679  */
680 void intel_pipe_update_end(struct intel_atomic_state *state,
681 			   struct intel_crtc *crtc)
682 {
683 	struct intel_crtc_state *new_crtc_state =
684 		intel_atomic_get_new_crtc_state(state, crtc);
685 	enum pipe pipe = crtc->pipe;
686 	int scanline_end = intel_get_crtc_scanline(crtc);
687 	u32 end_vbl_count = intel_crtc_get_vblank_counter(crtc);
688 	ktime_t end_vbl_time = ktime_get();
689 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
690 
691 	if (new_crtc_state->do_async_flip)
692 		goto out;
693 
694 	trace_intel_pipe_update_end(crtc, end_vbl_count, scanline_end);
695 
696 	/*
697 	 * Incase of mipi dsi command mode, we need to set frame update
698 	 * request for every commit.
699 	 */
700 	if (DISPLAY_VER(dev_priv) >= 11 &&
701 	    intel_crtc_has_type(new_crtc_state, INTEL_OUTPUT_DSI))
702 		icl_dsi_frame_update(new_crtc_state);
703 
704 	/* We're still in the vblank-evade critical section, this can't race.
705 	 * Would be slightly nice to just grab the vblank count and arm the
706 	 * event outside of the critical section - the spinlock might spin for a
707 	 * while ... */
708 	if (intel_crtc_needs_vblank_work(new_crtc_state)) {
709 		drm_vblank_work_schedule(&new_crtc_state->vblank_work,
710 					 drm_crtc_accurate_vblank_count(&crtc->base) + 1,
711 					 false);
712 	} else if (new_crtc_state->uapi.event) {
713 		drm_WARN_ON(&dev_priv->drm,
714 			    drm_crtc_vblank_get(&crtc->base) != 0);
715 
716 		spin_lock(&crtc->base.dev->event_lock);
717 		drm_crtc_arm_vblank_event(&crtc->base,
718 					  new_crtc_state->uapi.event);
719 		spin_unlock(&crtc->base.dev->event_lock);
720 
721 		new_crtc_state->uapi.event = NULL;
722 	}
723 
724 	/*
725 	 * Send VRR Push to terminate Vblank. If we are already in vblank
726 	 * this has to be done _after_ sampling the frame counter, as
727 	 * otherwise the push would immediately terminate the vblank and
728 	 * the sampled frame counter would correspond to the next frame
729 	 * instead of the current frame.
730 	 *
731 	 * There is a tiny race here (iff vblank evasion failed us) where
732 	 * we might sample the frame counter just before vmax vblank start
733 	 * but the push would be sent just after it. That would cause the
734 	 * push to affect the next frame instead of the current frame,
735 	 * which would cause the next frame to terminate already at vmin
736 	 * vblank start instead of vmax vblank start.
737 	 */
738 	intel_vrr_send_push(new_crtc_state);
739 
740 	local_irq_enable();
741 
742 	if (intel_vgpu_active(dev_priv))
743 		goto out;
744 
745 	if (crtc->debug.start_vbl_count &&
746 	    crtc->debug.start_vbl_count != end_vbl_count) {
747 		drm_err(&dev_priv->drm,
748 			"Atomic update failure on pipe %c (start=%u end=%u) time %lld us, min %d, max %d, scanline start %d, end %d\n",
749 			pipe_name(pipe), crtc->debug.start_vbl_count,
750 			end_vbl_count,
751 			ktime_us_delta(end_vbl_time,
752 				       crtc->debug.start_vbl_time),
753 			crtc->debug.min_vbl, crtc->debug.max_vbl,
754 			crtc->debug.scanline_start, scanline_end);
755 	}
756 
757 	dbg_vblank_evade(crtc, end_vbl_time);
758 
759 out:
760 	intel_psr_unlock(new_crtc_state);
761 }
762