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