aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/char/drm/i915_irq.c
blob: 4b4b2ce8986345a5f2d1eedb179756ba0e99d382 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
/* i915_irq.c -- IRQ support for the I915 -*- linux-c -*-
 */
/*
 * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
 * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

#include "drmP.h"
#include "drm.h"
#include "i915_drm.h"
#include "i915_drv.h"

#define USER_INT_FLAG (1<<1)
#define VSYNC_PIPEB_FLAG (1<<5)
#define VSYNC_PIPEA_FLAG (1<<7)

#define MAX_NOPID ((u32)~0)

/**
 * Emit blits for scheduled buffer swaps.
 *
 * This function will be called with the HW lock held.
 */
static void i915_vblank_tasklet(struct drm_device *dev)
{
	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
	unsigned long irqflags;
	struct list_head *list, *tmp, hits, *hit;
	int nhits, nrects, slice[2], upper[2], lower[2], i;
	unsigned counter[2] = { atomic_read(&dev->vbl_received),
				atomic_read(&dev->vbl_received2) };
	struct drm_drawable_info *drw;
	drm_i915_sarea_t *sarea_priv = dev_priv->sarea_priv;
	u32 cpp = dev_priv->cpp;
	u32 cmd = (cpp == 4) ? (XY_SRC_COPY_BLT_CMD |
				XY_SRC_COPY_BLT_WRITE_ALPHA |
				XY_SRC_COPY_BLT_WRITE_RGB)
			     : XY_SRC_COPY_BLT_CMD;
	u32 pitchropcpp = (sarea_priv->pitch * cpp) | (0xcc << 16) |
			  (cpp << 23) | (1 << 24);
	RING_LOCALS;

	DRM_DEBUG("\n");

	INIT_LIST_HEAD(&hits);

	nhits = nrects = 0;

	spin_lock_irqsave(&dev_priv->swaps_lock, irqflags);

	/* Find buffer swaps scheduled for this vertical blank */
	list_for_each_safe(list, tmp, &dev_priv->vbl_swaps.head) {
		drm_i915_vbl_swap_t *vbl_swap =
			list_entry(list, drm_i915_vbl_swap_t, head);

		if ((counter[vbl_swap->pipe] - vbl_swap->sequence) > (1<<23))
			continue;

		list_del(list);
		dev_priv->swaps_pending--;

		spin_unlock(&dev_priv->swaps_lock);
		spin_lock(&dev->drw_lock);

		drw = drm_get_drawable_info(dev, vbl_swap->drw_id);

		if (!drw) {
			spin_unlock(&dev->drw_lock);
			drm_free(vbl_swap, sizeof(*vbl_swap), DRM_MEM_DRIVER);
			spin_lock(&dev_priv->swaps_lock);
			continue;
		}

		list_for_each(hit, &hits) {
			drm_i915_vbl_swap_t *swap_cmp =
				list_entry(hit, drm_i915_vbl_swap_t, head);
			struct drm_drawable_info *drw_cmp =
				drm_get_drawable_info(dev, swap_cmp->drw_id);

			if (drw_cmp &&
			    drw_cmp->rects[0].y1 > drw->rects[0].y1) {
				list_add_tail(list, hit);
				break;
			}
		}

		spin_unlock(&dev->drw_lock);

		/* List of hits was empty, or we reached the end of it */
		if (hit == &hits)
			list_add_tail(list, hits.prev);

		nhits++;

		spin_lock(&dev_priv->swaps_lock);
	}

	if (nhits == 0) {
		spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);
		return;
	}

	spin_unlock(&dev_priv->swaps_lock);

	i915_kernel_lost_context(dev);

	BEGIN_LP_RING(6);

	OUT_RING(GFX_OP_DRAWRECT_INFO);
	OUT_RING(0);
	OUT_RING(0);
	OUT_RING(sarea_priv->width | sarea_priv->height << 16);
	OUT_RING(sarea_priv->width | sarea_priv->height << 16);
	OUT_RING(0);

	ADVANCE_LP_RING();

	sarea_priv->ctxOwner = DRM_KERNEL_CONTEXT;

	upper[0] = upper[1] = 0;
	slice[0] = max(sarea_priv->pipeA_h / nhits, 1);
	slice[1] = max(sarea_priv->pipeB_h / nhits, 1);
	lower[0] = sarea_priv->pipeA_y + slice[0];
	lower[1] = sarea_priv->pipeB_y + slice[0];

	spin_lock(&dev->drw_lock);

	/* Emit blits for buffer swaps, partitioning both outputs into as many
	 * slices as there are buffer swaps scheduled in order to avoid tearing
	 * (based on the assumption that a single buffer swap would always
	 * complete before scanout starts).
	 */
	for (i = 0; i++ < nhits;
	     upper[0] = lower[0], lower[0] += slice[0],
	     upper[1] = lower[1], lower[1] += slice[1]) {
		if (i == nhits)
			lower[0] = lower[1] = sarea_priv->height;

		list_for_each(hit, &hits) {
			drm_i915_vbl_swap_t *swap_hit =
				list_entry(hit, drm_i915_vbl_swap_t, head);
			struct drm_clip_rect *rect;
			int num_rects, pipe;
			unsigned short top, bottom;

			drw = drm_get_drawable_info(dev, swap_hit->drw_id);

			if (!drw)
				continue;

			rect = drw->rects;
			pipe = swap_hit->pipe;
			top = upper[pipe];
			bottom = lower[pipe];

			for (num_rects = drw->num_rects; num_rects--; rect++) {
				int y1 = max(rect->y1, top);
				int y2 = min(rect->y2, bottom);

				if (y1 >= y2)
					continue;

				BEGIN_LP_RING(8);

				OUT_RING(cmd);
				OUT_RING(pitchropcpp);
				OUT_RING((y1 << 16) | rect->x1);
				OUT_RING((y2 << 16) | rect->x2);
				OUT_RING(sarea_priv->front_offset);
				OUT_RING((y1 << 16) | rect->x1);
				OUT_RING(pitchropcpp & 0xffff);
				OUT_RING(sarea_priv->back_offset);

				ADVANCE_LP_RING();
			}
		}
	}

	spin_unlock_irqrestore(&dev->drw_lock, irqflags);

	list_for_each_safe(hit, tmp, &hits) {
		drm_i915_vbl_swap_t *swap_hit =
			list_entry(hit, drm_i915_vbl_swap_t, head);

		list_del(hit);

		drm_free(swap_hit, sizeof(*swap_hit), DRM_MEM_DRIVER);
	}
}

irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
{
	struct drm_device *dev = (struct drm_device *) arg;
	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
	u16 temp;

	temp = I915_READ16(I915REG_INT_IDENTITY_R);

	temp &= (USER_INT_FLAG | VSYNC_PIPEA_FLAG | VSYNC_PIPEB_FLAG);

	DRM_DEBUG("%s flag=%08x\n", __FUNCTION__, temp);

	if (temp == 0)
		return IRQ_NONE;

	I915_WRITE16(I915REG_INT_IDENTITY_R, temp);

	dev_priv->sarea_priv->last_dispatch = READ_BREADCRUMB(dev_priv);

	if (temp & USER_INT_FLAG)
		DRM_WAKEUP(&dev_priv->irq_queue);

	if (temp & (VSYNC_PIPEA_FLAG | VSYNC_PIPEB_FLAG)) {
		int vblank_pipe = dev_priv->vblank_pipe;

		if ((vblank_pipe &
		     (DRM_I915_VBLANK_PIPE_A | DRM_I915_VBLANK_PIPE_B))
		    == (DRM_I915_VBLANK_PIPE_A | DRM_I915_VBLANK_PIPE_B)) {
			if (temp & VSYNC_PIPEA_FLAG)
				atomic_inc(&dev->vbl_received);
			if (temp & VSYNC_PIPEB_FLAG)
				atomic_inc(&dev->vbl_received2);
		} else if (((temp & VSYNC_PIPEA_FLAG) &&
			    (vblank_pipe & DRM_I915_VBLANK_PIPE_A)) ||
			   ((temp & VSYNC_PIPEB_FLAG) &&
			    (vblank_pipe & DRM_I915_VBLANK_PIPE_B)))
			atomic_inc(&dev->vbl_received);

		DRM_WAKEUP(&dev->vbl_queue);
		drm_vbl_send_signals(dev);

		if (dev_priv->swaps_pending > 0)
			drm_locked_tasklet(dev, i915_vblank_tasklet);
	}

	return IRQ_HANDLED;
}

static int i915_emit_irq(struct drm_device * dev)
{
	drm_i915_private_t *dev_priv = dev->dev_private;
	RING_LOCALS;

	i915_kernel_lost_context(dev);

	DRM_DEBUG("%s\n", __FUNCTION__);

	dev_priv->sarea_priv->last_enqueue = ++dev_priv->counter;

	if (dev_priv->counter > 0x7FFFFFFFUL)
		dev_priv->sarea_priv->last_enqueue = dev_priv->counter = 1;

	BEGIN_LP_RING(6);
	OUT_RING(CMD_STORE_DWORD_IDX);
	OUT_RING(20);
	OUT_RING(dev_priv->counter);
	OUT_RING(0);
	OUT_RING(0);
	OUT_RING(GFX_OP_USER_INTERRUPT);
	ADVANCE_LP_RING();
	
	return dev_priv->counter;
}

static int i915_wait_irq(struct drm_device * dev, int irq_nr)
{
	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
	int ret = 0;

	DRM_DEBUG("%s irq_nr=%d breadcrumb=%d\n", __FUNCTION__, irq_nr,
		  READ_BREADCRUMB(dev_priv));

	if (READ_BREADCRUMB(dev_priv) >= irq_nr)
		return 0;

	dev_priv->sarea_priv->perf_boxes |= I915_BOX_WAIT;

	DRM_WAIT_ON(ret, dev_priv->irq_queue, 3 * DRM_HZ,
		    READ_BREADCRUMB(dev_priv) >= irq_nr);

	if (ret == DRM_ERR(EBUSY)) {
		DRM_ERROR("%s: EBUSY -- rec: %d emitted: %d\n",
			  __FUNCTION__,
			  READ_BREADCRUMB(dev_priv), (int)dev_priv->counter);
	}

	dev_priv->sarea_priv->last_dispatch = READ_BREADCRUMB(dev_priv);
	return ret;
}

static int i915_driver_vblank_do_wait(struct drm_device *dev, unsigned int *sequence,
				      atomic_t *counter)
{
	drm_i915_private_t *dev_priv = dev->dev_private;
	unsigned int cur_vblank;
	int ret = 0;

	if (!dev_priv) {
		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
		return DRM_ERR(EINVAL);
	}

	DRM_WAIT_ON(ret, dev->vbl_queue, 3 * DRM_HZ,
		    (((cur_vblank = atomic_read(counter))
			- *sequence) <= (1<<23)));
	
	*sequence = cur_vblank;

	return ret;
}


int i915_driver_vblank_wait(struct drm_device *dev, unsigned int *sequence)
{
	return i915_driver_vblank_do_wait(dev, sequence, &dev->vbl_received);
}

int i915_driver_vblank_wait2(struct drm_device *dev, unsigned int *sequence)
{
	return i915_driver_vblank_do_wait(dev, sequence, &dev->vbl_received2);
}

/* Needs the lock as it touches the ring.
 */
int i915_irq_emit(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_i915_private_t *dev_priv = dev->dev_private;
	drm_i915_irq_emit_t emit;
	int result;

	LOCK_TEST_WITH_RETURN(dev, filp);

	if (!dev_priv) {
		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
		return DRM_ERR(EINVAL);
	}

	DRM_COPY_FROM_USER_IOCTL(emit, (drm_i915_irq_emit_t __user *) data,
				 sizeof(emit));

	result = i915_emit_irq(dev);

	if (DRM_COPY_TO_USER(emit.irq_seq, &result, sizeof(int))) {
		DRM_ERROR("copy_to_user\n");
		return DRM_ERR(EFAULT);
	}

	return 0;
}

/* Doesn't need the hardware lock.
 */
int i915_irq_wait(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_i915_private_t *dev_priv = dev->dev_private;
	drm_i915_irq_wait_t irqwait;

	if (!dev_priv) {
		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
		return DRM_ERR(EINVAL);
	}

	DRM_COPY_FROM_USER_IOCTL(irqwait, (drm_i915_irq_wait_t __user *) data,
				 sizeof(irqwait));

	return i915_wait_irq(dev, irqwait.irq_seq);
}

static void i915_enable_interrupt (struct drm_device *dev)
{
	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
	u16 flag;

	flag = 0;
	if (dev_priv->vblank_pipe & DRM_I915_VBLANK_PIPE_A)
		flag |= VSYNC_PIPEA_FLAG;
	if (dev_priv->vblank_pipe & DRM_I915_VBLANK_PIPE_B)
		flag |= VSYNC_PIPEB_FLAG;

	I915_WRITE16(I915REG_INT_ENABLE_R, USER_INT_FLAG | flag);
}

/* Set the vblank monitor pipe
 */
int i915_vblank_pipe_set(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_i915_private_t *dev_priv = dev->dev_private;
	drm_i915_vblank_pipe_t pipe;

	if (!dev_priv) {
		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
		return DRM_ERR(EINVAL);
	}

	DRM_COPY_FROM_USER_IOCTL(pipe, (drm_i915_vblank_pipe_t __user *) data,
				 sizeof(pipe));

	if (pipe.pipe & ~(DRM_I915_VBLANK_PIPE_A|DRM_I915_VBLANK_PIPE_B)) {
		DRM_ERROR("%s called with invalid pipe 0x%x\n", 
			  __FUNCTION__, pipe.pipe);
		return DRM_ERR(EINVAL);
	}

	dev_priv->vblank_pipe = pipe.pipe;

	i915_enable_interrupt (dev);

	return 0;
}

int i915_vblank_pipe_get(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_i915_private_t *dev_priv = dev->dev_private;
	drm_i915_vblank_pipe_t pipe;
	u16 flag;

	if (!dev_priv) {
		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
		return DRM_ERR(EINVAL);
	}

	flag = I915_READ(I915REG_INT_ENABLE_R);
	pipe.pipe = 0;
	if (flag & VSYNC_PIPEA_FLAG)
		pipe.pipe |= DRM_I915_VBLANK_PIPE_A;
	if (flag & VSYNC_PIPEB_FLAG)
		pipe.pipe |= DRM_I915_VBLANK_PIPE_B;
	DRM_COPY_TO_USER_IOCTL((drm_i915_vblank_pipe_t __user *) data, pipe,
				 sizeof(pipe));
	return 0;
}

/**
 * Schedule buffer swap at given vertical blank.
 */
int i915_vblank_swap(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_i915_private_t *dev_priv = dev->dev_private;
	drm_i915_vblank_swap_t swap;
	drm_i915_vbl_swap_t *vbl_swap;
	unsigned int pipe, seqtype, curseq;
	unsigned long irqflags;
	struct list_head *list;

	if (!dev_priv) {
		DRM_ERROR("%s called with no initialization\n", __func__);
		return DRM_ERR(EINVAL);
	}

	if (dev_priv->sarea_priv->rotation) {
		DRM_DEBUG("Rotation not supported\n");
		return DRM_ERR(EINVAL);
	}

	DRM_COPY_FROM_USER_IOCTL(swap, (drm_i915_vblank_swap_t __user *) data,
				 sizeof(swap));

	if (swap.seqtype & ~(_DRM_VBLANK_RELATIVE | _DRM_VBLANK_ABSOLUTE |
			     _DRM_VBLANK_SECONDARY | _DRM_VBLANK_NEXTONMISS)) {
		DRM_ERROR("Invalid sequence type 0x%x\n", swap.seqtype);
		return DRM_ERR(EINVAL);
	}

	pipe = (swap.seqtype & _DRM_VBLANK_SECONDARY) ? 1 : 0;

	seqtype = swap.seqtype & (_DRM_VBLANK_RELATIVE | _DRM_VBLANK_ABSOLUTE);

	if (!(dev_priv->vblank_pipe & (1 << pipe))) {
		DRM_ERROR("Invalid pipe %d\n", pipe);
		return DRM_ERR(EINVAL);
	}

	spin_lock_irqsave(&dev->drw_lock, irqflags);

	if (!drm_get_drawable_info(dev, swap.drawable)) {
		spin_unlock_irqrestore(&dev->drw_lock, irqflags);
		DRM_DEBUG("Invalid drawable ID %d\n", swap.drawable);
		return DRM_ERR(EINVAL);
	}

	spin_unlock_irqrestore(&dev->drw_lock, irqflags);

	curseq = atomic_read(pipe ? &dev->vbl_received2 : &dev->vbl_received);

	if (seqtype == _DRM_VBLANK_RELATIVE)
		swap.sequence += curseq;

	if ((curseq - swap.sequence) <= (1<<23)) {
		if (swap.seqtype & _DRM_VBLANK_NEXTONMISS) {
			swap.sequence = curseq + 1;
		} else {
			DRM_DEBUG("Missed target sequence\n");
			return DRM_ERR(EINVAL);
		}
	}

	spin_lock_irqsave(&dev_priv->swaps_lock, irqflags);

	list_for_each(list, &dev_priv->vbl_swaps.head) {
		vbl_swap = list_entry(list, drm_i915_vbl_swap_t, head);

		if (vbl_swap->drw_id == swap.drawable &&
		    vbl_swap->pipe == pipe &&
		    vbl_swap->sequence == swap.sequence) {
			spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);
			DRM_DEBUG("Already scheduled\n");
			return 0;
		}
	}

	spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);

	if (dev_priv->swaps_pending >= 100) {
		DRM_DEBUG("Too many swaps queued\n");
		return DRM_ERR(EBUSY);
	}

	vbl_swap = drm_calloc(1, sizeof(vbl_swap), DRM_MEM_DRIVER);

	if (!vbl_swap) {
		DRM_ERROR("Failed to allocate memory to queue swap\n");
		return DRM_ERR(ENOMEM);
	}

	DRM_DEBUG("\n");

	vbl_swap->drw_id = swap.drawable;
	vbl_swap->pipe = pipe;
	vbl_swap->sequence = swap.sequence;

	spin_lock_irqsave(&dev_priv->swaps_lock, irqflags);

	list_add_tail((struct list_head *)vbl_swap, &dev_priv->vbl_swaps.head);
	dev_priv->swaps_pending++;

	spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);

	DRM_COPY_TO_USER_IOCTL((drm_i915_vblank_swap_t __user *) data, swap,
			       sizeof(swap));

	return 0;
}

/* drm_dma.h hooks
*/
void i915_driver_irq_preinstall(struct drm_device * dev)
{
	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;

	I915_WRITE16(I915REG_HWSTAM, 0xfffe);
	I915_WRITE16(I915REG_INT_MASK_R, 0x0);
	I915_WRITE16(I915REG_INT_ENABLE_R, 0x0);
}

void i915_driver_irq_postinstall(struct drm_device * dev)
{
	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;

	spin_lock_init(&dev_priv->swaps_lock);
	INIT_LIST_HEAD(&dev_priv->vbl_swaps.head);
	dev_priv->swaps_pending = 0;

	if (!dev_priv->vblank_pipe)
		dev_priv->vblank_pipe = DRM_I915_VBLANK_PIPE_A;
	i915_enable_interrupt(dev);
	DRM_INIT_WAITQUEUE(&dev_priv->irq_queue);
}

void i915_driver_irq_uninstall(struct drm_device * dev)
{
	drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
	u16 temp;

	if (!dev_priv)
		return;

	I915_WRITE16(I915REG_HWSTAM, 0xffff);
	I915_WRITE16(I915REG_INT_MASK_R, 0xffff);
	I915_WRITE16(I915REG_INT_ENABLE_R, 0x0);

	temp = I915_READ16(I915REG_INT_IDENTITY_R);
	I915_WRITE16(I915REG_INT_IDENTITY_R, temp);
}