ASoC: soc-compress: Send correct stream event for capture start
[firefly-linux-kernel-4.4.55.git] / drivers / gpu / drm / qxl / qxl_cmd.c
1 /*
2  * Copyright 2013 Red Hat Inc.
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 shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Authors: Dave Airlie
23  *          Alon Levy
24  */
25
26 /* QXL cmd/ring handling */
27
28 #include "qxl_drv.h"
29 #include "qxl_object.h"
30
31 static int qxl_reap_surface_id(struct qxl_device *qdev, int max_to_reap);
32
33 struct ring {
34         struct qxl_ring_header      header;
35         uint8_t                     elements[0];
36 };
37
38 struct qxl_ring {
39         struct ring            *ring;
40         int                     element_size;
41         int                     n_elements;
42         int                     prod_notify;
43         wait_queue_head_t      *push_event;
44         spinlock_t             lock;
45 };
46
47 void qxl_ring_free(struct qxl_ring *ring)
48 {
49         kfree(ring);
50 }
51
52 struct qxl_ring *
53 qxl_ring_create(struct qxl_ring_header *header,
54                 int element_size,
55                 int n_elements,
56                 int prod_notify,
57                 bool set_prod_notify,
58                 wait_queue_head_t *push_event)
59 {
60         struct qxl_ring *ring;
61
62         ring = kmalloc(sizeof(*ring), GFP_KERNEL);
63         if (!ring)
64                 return NULL;
65
66         ring->ring = (struct ring *)header;
67         ring->element_size = element_size;
68         ring->n_elements = n_elements;
69         ring->prod_notify = prod_notify;
70         ring->push_event = push_event;
71         if (set_prod_notify)
72                 header->notify_on_prod = ring->n_elements;
73         spin_lock_init(&ring->lock);
74         return ring;
75 }
76
77 static int qxl_check_header(struct qxl_ring *ring)
78 {
79         int ret;
80         struct qxl_ring_header *header = &(ring->ring->header);
81         unsigned long flags;
82         spin_lock_irqsave(&ring->lock, flags);
83         ret = header->prod - header->cons < header->num_items;
84         if (ret == 0)
85                 header->notify_on_cons = header->cons + 1;
86         spin_unlock_irqrestore(&ring->lock, flags);
87         return ret;
88 }
89
90 static int qxl_check_idle(struct qxl_ring *ring)
91 {
92         int ret;
93         struct qxl_ring_header *header = &(ring->ring->header);
94         unsigned long flags;
95         spin_lock_irqsave(&ring->lock, flags);
96         ret = header->prod == header->cons;
97         spin_unlock_irqrestore(&ring->lock, flags);
98         return ret;
99 }
100
101 int qxl_ring_push(struct qxl_ring *ring,
102                   const void *new_elt, bool interruptible)
103 {
104         struct qxl_ring_header *header = &(ring->ring->header);
105         uint8_t *elt;
106         int idx, ret;
107         unsigned long flags;
108         spin_lock_irqsave(&ring->lock, flags);
109         if (header->prod - header->cons == header->num_items) {
110                 header->notify_on_cons = header->cons + 1;
111                 mb();
112                 spin_unlock_irqrestore(&ring->lock, flags);
113                 if (!drm_can_sleep()) {
114                         while (!qxl_check_header(ring))
115                                 udelay(1);
116                 } else {
117                         if (interruptible) {
118                                 ret = wait_event_interruptible(*ring->push_event,
119                                                                qxl_check_header(ring));
120                                 if (ret)
121                                         return ret;
122                         } else {
123                                 wait_event(*ring->push_event,
124                                            qxl_check_header(ring));
125                         }
126
127                 }
128                 spin_lock_irqsave(&ring->lock, flags);
129         }
130
131         idx = header->prod & (ring->n_elements - 1);
132         elt = ring->ring->elements + idx * ring->element_size;
133
134         memcpy((void *)elt, new_elt, ring->element_size);
135
136         header->prod++;
137
138         mb();
139
140         if (header->prod == header->notify_on_prod)
141                 outb(0, ring->prod_notify);
142
143         spin_unlock_irqrestore(&ring->lock, flags);
144         return 0;
145 }
146
147 static bool qxl_ring_pop(struct qxl_ring *ring,
148                          void *element)
149 {
150         volatile struct qxl_ring_header *header = &(ring->ring->header);
151         volatile uint8_t *ring_elt;
152         int idx;
153         unsigned long flags;
154         spin_lock_irqsave(&ring->lock, flags);
155         if (header->cons == header->prod) {
156                 header->notify_on_prod = header->cons + 1;
157                 spin_unlock_irqrestore(&ring->lock, flags);
158                 return false;
159         }
160
161         idx = header->cons & (ring->n_elements - 1);
162         ring_elt = ring->ring->elements + idx * ring->element_size;
163
164         memcpy(element, (void *)ring_elt, ring->element_size);
165
166         header->cons++;
167
168         spin_unlock_irqrestore(&ring->lock, flags);
169         return true;
170 }
171
172 int
173 qxl_push_command_ring_release(struct qxl_device *qdev, struct qxl_release *release,
174                               uint32_t type, bool interruptible)
175 {
176         struct qxl_command cmd;
177
178         cmd.type = type;
179         cmd.data = qxl_bo_physical_address(qdev, release->bos[0], release->release_offset);
180
181         return qxl_ring_push(qdev->command_ring, &cmd, interruptible);
182 }
183
184 int
185 qxl_push_cursor_ring_release(struct qxl_device *qdev, struct qxl_release *release,
186                              uint32_t type, bool interruptible)
187 {
188         struct qxl_command cmd;
189
190         cmd.type = type;
191         cmd.data = qxl_bo_physical_address(qdev, release->bos[0], release->release_offset);
192
193         return qxl_ring_push(qdev->cursor_ring, &cmd, interruptible);
194 }
195
196 bool qxl_queue_garbage_collect(struct qxl_device *qdev, bool flush)
197 {
198         if (!qxl_check_idle(qdev->release_ring)) {
199                 queue_work(qdev->gc_queue, &qdev->gc_work);
200                 if (flush)
201                         flush_work(&qdev->gc_work);
202                 return true;
203         }
204         return false;
205 }
206
207 int qxl_garbage_collect(struct qxl_device *qdev)
208 {
209         struct qxl_release *release;
210         uint64_t id, next_id;
211         int i = 0;
212         int ret;
213         union qxl_release_info *info;
214
215         while (qxl_ring_pop(qdev->release_ring, &id)) {
216                 QXL_INFO(qdev, "popped %lld\n", id);
217                 while (id) {
218                         release = qxl_release_from_id_locked(qdev, id);
219                         if (release == NULL)
220                                 break;
221
222                         ret = qxl_release_reserve(qdev, release, false);
223                         if (ret) {
224                                 qxl_io_log(qdev, "failed to reserve release on garbage collect %lld\n", id);
225                                 DRM_ERROR("failed to reserve release %lld\n", id);
226                         }
227
228                         info = qxl_release_map(qdev, release);
229                         next_id = info->next;
230                         qxl_release_unmap(qdev, release, info);
231
232                         qxl_release_unreserve(qdev, release);
233                         QXL_INFO(qdev, "popped %lld, next %lld\n", id,
234                                 next_id);
235
236                         switch (release->type) {
237                         case QXL_RELEASE_DRAWABLE:
238                         case QXL_RELEASE_SURFACE_CMD:
239                         case QXL_RELEASE_CURSOR_CMD:
240                                 break;
241                         default:
242                                 DRM_ERROR("unexpected release type\n");
243                                 break;
244                         }
245                         id = next_id;
246
247                         qxl_release_free(qdev, release);
248                         ++i;
249                 }
250         }
251
252         QXL_INFO(qdev, "%s: %lld\n", __func__, i);
253
254         return i;
255 }
256
257 int qxl_alloc_bo_reserved(struct qxl_device *qdev, unsigned long size,
258                           struct qxl_bo **_bo)
259 {
260         struct qxl_bo *bo;
261         int ret;
262
263         ret = qxl_bo_create(qdev, size, false /* not kernel - device */,
264                             QXL_GEM_DOMAIN_VRAM, NULL, &bo);
265         if (ret) {
266                 DRM_ERROR("failed to allocate VRAM BO\n");
267                 return ret;
268         }
269         ret = qxl_bo_reserve(bo, false);
270         if (unlikely(ret != 0))
271                 goto out_unref;
272
273         *_bo = bo;
274         return 0;
275 out_unref:
276         qxl_bo_unref(&bo);
277         return 0;
278 }
279
280 static int wait_for_io_cmd_user(struct qxl_device *qdev, uint8_t val, long port)
281 {
282         int irq_num;
283         long addr = qdev->io_base + port;
284         int ret;
285
286         mutex_lock(&qdev->async_io_mutex);
287         irq_num = atomic_read(&qdev->irq_received_io_cmd);
288
289
290         if (qdev->last_sent_io_cmd > irq_num) {
291                 ret = wait_event_interruptible(qdev->io_cmd_event,
292                                                atomic_read(&qdev->irq_received_io_cmd) > irq_num);
293                 if (ret)
294                         goto out;
295                 irq_num = atomic_read(&qdev->irq_received_io_cmd);
296         }
297         outb(val, addr);
298         qdev->last_sent_io_cmd = irq_num + 1;
299         ret = wait_event_interruptible(qdev->io_cmd_event,
300                                        atomic_read(&qdev->irq_received_io_cmd) > irq_num);
301 out:
302         mutex_unlock(&qdev->async_io_mutex);
303         return ret;
304 }
305
306 static void wait_for_io_cmd(struct qxl_device *qdev, uint8_t val, long port)
307 {
308         int ret;
309
310 restart:
311         ret = wait_for_io_cmd_user(qdev, val, port);
312         if (ret == -ERESTARTSYS)
313                 goto restart;
314 }
315
316 int qxl_io_update_area(struct qxl_device *qdev, struct qxl_bo *surf,
317                         const struct qxl_rect *area)
318 {
319         int surface_id;
320         uint32_t surface_width, surface_height;
321         int ret;
322
323         if (!surf->hw_surf_alloc)
324                 DRM_ERROR("got io update area with no hw surface\n");
325
326         if (surf->is_primary)
327                 surface_id = 0;
328         else
329                 surface_id = surf->surface_id;
330         surface_width = surf->surf.width;
331         surface_height = surf->surf.height;
332
333         if (area->left < 0 || area->top < 0 ||
334             area->right > surface_width || area->bottom > surface_height) {
335                 qxl_io_log(qdev, "%s: not doing area update for "
336                            "%d, (%d,%d,%d,%d) (%d,%d)\n", __func__, surface_id, area->left,
337                            area->top, area->right, area->bottom, surface_width, surface_height);
338                 return -EINVAL;
339         }
340         mutex_lock(&qdev->update_area_mutex);
341         qdev->ram_header->update_area = *area;
342         qdev->ram_header->update_surface = surface_id;
343         ret = wait_for_io_cmd_user(qdev, 0, QXL_IO_UPDATE_AREA_ASYNC);
344         mutex_unlock(&qdev->update_area_mutex);
345         return ret;
346 }
347
348 void qxl_io_notify_oom(struct qxl_device *qdev)
349 {
350         outb(0, qdev->io_base + QXL_IO_NOTIFY_OOM);
351 }
352
353 void qxl_io_flush_release(struct qxl_device *qdev)
354 {
355         outb(0, qdev->io_base + QXL_IO_FLUSH_RELEASE);
356 }
357
358 void qxl_io_flush_surfaces(struct qxl_device *qdev)
359 {
360         wait_for_io_cmd(qdev, 0, QXL_IO_FLUSH_SURFACES_ASYNC);
361 }
362
363
364 void qxl_io_destroy_primary(struct qxl_device *qdev)
365 {
366         wait_for_io_cmd(qdev, 0, QXL_IO_DESTROY_PRIMARY_ASYNC);
367 }
368
369 void qxl_io_create_primary(struct qxl_device *qdev, unsigned width,
370                            unsigned height, unsigned offset, struct qxl_bo *bo)
371 {
372         struct qxl_surface_create *create;
373
374         QXL_INFO(qdev, "%s: qdev %p, ram_header %p\n", __func__, qdev,
375                  qdev->ram_header);
376         create = &qdev->ram_header->create_surface;
377         create->format = bo->surf.format;
378         create->width = width;
379         create->height = height;
380         create->stride = bo->surf.stride;
381         create->mem = qxl_bo_physical_address(qdev, bo, offset);
382
383         QXL_INFO(qdev, "%s: mem = %llx, from %p\n", __func__, create->mem,
384                  bo->kptr);
385
386         create->flags = QXL_SURF_FLAG_KEEP_DATA;
387         create->type = QXL_SURF_TYPE_PRIMARY;
388
389         wait_for_io_cmd(qdev, 0, QXL_IO_CREATE_PRIMARY_ASYNC);
390 }
391
392 void qxl_io_memslot_add(struct qxl_device *qdev, uint8_t id)
393 {
394         QXL_INFO(qdev, "qxl_memslot_add %d\n", id);
395         wait_for_io_cmd(qdev, id, QXL_IO_MEMSLOT_ADD_ASYNC);
396 }
397
398 void qxl_io_log(struct qxl_device *qdev, const char *fmt, ...)
399 {
400         va_list args;
401
402         va_start(args, fmt);
403         vsnprintf(qdev->ram_header->log_buf, QXL_LOG_BUF_SIZE, fmt, args);
404         va_end(args);
405         /*
406          * DO not do a DRM output here - this will call printk, which will
407          * call back into qxl for rendering (qxl_fb)
408          */
409         outb(0, qdev->io_base + QXL_IO_LOG);
410 }
411
412 void qxl_io_reset(struct qxl_device *qdev)
413 {
414         outb(0, qdev->io_base + QXL_IO_RESET);
415 }
416
417 void qxl_io_monitors_config(struct qxl_device *qdev)
418 {
419         qxl_io_log(qdev, "%s: %d [%dx%d+%d+%d]\n", __func__,
420                    qdev->monitors_config ?
421                    qdev->monitors_config->count : -1,
422                    qdev->monitors_config && qdev->monitors_config->count ?
423                    qdev->monitors_config->heads[0].width : -1,
424                    qdev->monitors_config && qdev->monitors_config->count ?
425                    qdev->monitors_config->heads[0].height : -1,
426                    qdev->monitors_config && qdev->monitors_config->count ?
427                    qdev->monitors_config->heads[0].x : -1,
428                    qdev->monitors_config && qdev->monitors_config->count ?
429                    qdev->monitors_config->heads[0].y : -1
430                    );
431
432         wait_for_io_cmd(qdev, 0, QXL_IO_MONITORS_CONFIG_ASYNC);
433 }
434
435 int qxl_surface_id_alloc(struct qxl_device *qdev,
436                       struct qxl_bo *surf)
437 {
438         uint32_t handle;
439         int idr_ret;
440         int count = 0;
441 again:
442         idr_preload(GFP_ATOMIC);
443         spin_lock(&qdev->surf_id_idr_lock);
444         idr_ret = idr_alloc(&qdev->surf_id_idr, NULL, 1, 0, GFP_NOWAIT);
445         spin_unlock(&qdev->surf_id_idr_lock);
446         idr_preload_end();
447         if (idr_ret < 0)
448                 return idr_ret;
449         handle = idr_ret;
450
451         if (handle >= qdev->rom->n_surfaces) {
452                 count++;
453                 spin_lock(&qdev->surf_id_idr_lock);
454                 idr_remove(&qdev->surf_id_idr, handle);
455                 spin_unlock(&qdev->surf_id_idr_lock);
456                 qxl_reap_surface_id(qdev, 2);
457                 goto again;
458         }
459         surf->surface_id = handle;
460
461         spin_lock(&qdev->surf_id_idr_lock);
462         qdev->last_alloced_surf_id = handle;
463         spin_unlock(&qdev->surf_id_idr_lock);
464         return 0;
465 }
466
467 void qxl_surface_id_dealloc(struct qxl_device *qdev,
468                             uint32_t surface_id)
469 {
470         spin_lock(&qdev->surf_id_idr_lock);
471         idr_remove(&qdev->surf_id_idr, surface_id);
472         spin_unlock(&qdev->surf_id_idr_lock);
473 }
474
475 int qxl_hw_surface_alloc(struct qxl_device *qdev,
476                          struct qxl_bo *surf,
477                          struct ttm_mem_reg *new_mem)
478 {
479         struct qxl_surface_cmd *cmd;
480         struct qxl_release *release;
481         int ret;
482
483         if (surf->hw_surf_alloc)
484                 return 0;
485
486         ret = qxl_alloc_surface_release_reserved(qdev, QXL_SURFACE_CMD_CREATE,
487                                                  NULL,
488                                                  &release);
489         if (ret)
490                 return ret;
491
492         cmd = (struct qxl_surface_cmd *)qxl_release_map(qdev, release);
493         cmd->type = QXL_SURFACE_CMD_CREATE;
494         cmd->u.surface_create.format = surf->surf.format;
495         cmd->u.surface_create.width = surf->surf.width;
496         cmd->u.surface_create.height = surf->surf.height;
497         cmd->u.surface_create.stride = surf->surf.stride;
498         if (new_mem) {
499                 int slot_id = surf->type == QXL_GEM_DOMAIN_VRAM ? qdev->main_mem_slot : qdev->surfaces_mem_slot;
500                 struct qxl_memslot *slot = &(qdev->mem_slots[slot_id]);
501
502                 /* TODO - need to hold one of the locks to read tbo.offset */
503                 cmd->u.surface_create.data = slot->high_bits;
504
505                 cmd->u.surface_create.data |= (new_mem->start << PAGE_SHIFT) + surf->tbo.bdev->man[new_mem->mem_type].gpu_offset;
506         } else
507                 cmd->u.surface_create.data = qxl_bo_physical_address(qdev, surf, 0);
508         cmd->surface_id = surf->surface_id;
509         qxl_release_unmap(qdev, release, &cmd->release_info);
510
511         surf->surf_create = release;
512
513         /* no need to add a release to the fence for this bo,
514            since it is only released when we ask to destroy the surface
515            and it would never signal otherwise */
516         qxl_fence_releaseable(qdev, release);
517
518         qxl_push_command_ring_release(qdev, release, QXL_CMD_SURFACE, false);
519
520         qxl_release_unreserve(qdev, release);
521
522         surf->hw_surf_alloc = true;
523         spin_lock(&qdev->surf_id_idr_lock);
524         idr_replace(&qdev->surf_id_idr, surf, surf->surface_id);
525         spin_unlock(&qdev->surf_id_idr_lock);
526         return 0;
527 }
528
529 int qxl_hw_surface_dealloc(struct qxl_device *qdev,
530                            struct qxl_bo *surf)
531 {
532         struct qxl_surface_cmd *cmd;
533         struct qxl_release *release;
534         int ret;
535         int id;
536
537         if (!surf->hw_surf_alloc)
538                 return 0;
539
540         ret = qxl_alloc_surface_release_reserved(qdev, QXL_SURFACE_CMD_DESTROY,
541                                                  surf->surf_create,
542                                                  &release);
543         if (ret)
544                 return ret;
545
546         surf->surf_create = NULL;
547         /* remove the surface from the idr, but not the surface id yet */
548         spin_lock(&qdev->surf_id_idr_lock);
549         idr_replace(&qdev->surf_id_idr, NULL, surf->surface_id);
550         spin_unlock(&qdev->surf_id_idr_lock);
551         surf->hw_surf_alloc = false;
552
553         id = surf->surface_id;
554         surf->surface_id = 0;
555
556         release->surface_release_id = id;
557         cmd = (struct qxl_surface_cmd *)qxl_release_map(qdev, release);
558         cmd->type = QXL_SURFACE_CMD_DESTROY;
559         cmd->surface_id = id;
560         qxl_release_unmap(qdev, release, &cmd->release_info);
561
562         qxl_fence_releaseable(qdev, release);
563
564         qxl_push_command_ring_release(qdev, release, QXL_CMD_SURFACE, false);
565
566         qxl_release_unreserve(qdev, release);
567
568
569         return 0;
570 }
571
572 int qxl_update_surface(struct qxl_device *qdev, struct qxl_bo *surf)
573 {
574         struct qxl_rect rect;
575         int ret;
576
577         /* if we are evicting, we need to make sure the surface is up
578            to date */
579         rect.left = 0;
580         rect.right = surf->surf.width;
581         rect.top = 0;
582         rect.bottom = surf->surf.height;
583 retry:
584         ret = qxl_io_update_area(qdev, surf, &rect);
585         if (ret == -ERESTARTSYS)
586                 goto retry;
587         return ret;
588 }
589
590 static void qxl_surface_evict_locked(struct qxl_device *qdev, struct qxl_bo *surf, bool do_update_area)
591 {
592         /* no need to update area if we are just freeing the surface normally */
593         if (do_update_area)
594                 qxl_update_surface(qdev, surf);
595
596         /* nuke the surface id at the hw */
597         qxl_hw_surface_dealloc(qdev, surf);
598 }
599
600 void qxl_surface_evict(struct qxl_device *qdev, struct qxl_bo *surf, bool do_update_area)
601 {
602         mutex_lock(&qdev->surf_evict_mutex);
603         qxl_surface_evict_locked(qdev, surf, do_update_area);
604         mutex_unlock(&qdev->surf_evict_mutex);
605 }
606
607 static int qxl_reap_surf(struct qxl_device *qdev, struct qxl_bo *surf, bool stall)
608 {
609         int ret;
610
611         ret = qxl_bo_reserve(surf, false);
612         if (ret == -EBUSY)
613                 return -EBUSY;
614
615         if (surf->fence.num_active_releases > 0 && stall == false) {
616                 qxl_bo_unreserve(surf);
617                 return -EBUSY;
618         }
619
620         if (stall)
621                 mutex_unlock(&qdev->surf_evict_mutex);
622
623         spin_lock(&surf->tbo.bdev->fence_lock);
624         ret = ttm_bo_wait(&surf->tbo, true, true, !stall);
625         spin_unlock(&surf->tbo.bdev->fence_lock);
626
627         if (stall)
628                 mutex_lock(&qdev->surf_evict_mutex);
629         if (ret == -EBUSY) {
630                 qxl_bo_unreserve(surf);
631                 return -EBUSY;
632         }
633
634         qxl_surface_evict_locked(qdev, surf, true);
635         qxl_bo_unreserve(surf);
636         return 0;
637 }
638
639 static int qxl_reap_surface_id(struct qxl_device *qdev, int max_to_reap)
640 {
641         int num_reaped = 0;
642         int i, ret;
643         bool stall = false;
644         int start = 0;
645
646         mutex_lock(&qdev->surf_evict_mutex);
647 again:
648
649         spin_lock(&qdev->surf_id_idr_lock);
650         start = qdev->last_alloced_surf_id + 1;
651         spin_unlock(&qdev->surf_id_idr_lock);
652
653         for (i = start; i < start + qdev->rom->n_surfaces; i++) {
654                 void *objptr;
655                 int surfid = i % qdev->rom->n_surfaces;
656
657                 /* this avoids the case where the objects is in the
658                    idr but has been evicted half way - its makes
659                    the idr lookup atomic with the eviction */
660                 spin_lock(&qdev->surf_id_idr_lock);
661                 objptr = idr_find(&qdev->surf_id_idr, surfid);
662                 spin_unlock(&qdev->surf_id_idr_lock);
663
664                 if (!objptr)
665                         continue;
666
667                 ret = qxl_reap_surf(qdev, objptr, stall);
668                 if (ret == 0)
669                         num_reaped++;
670                 if (num_reaped >= max_to_reap)
671                         break;
672         }
673         if (num_reaped == 0 && stall == false) {
674                 stall = true;
675                 goto again;
676         }
677
678         mutex_unlock(&qdev->surf_evict_mutex);
679         if (num_reaped) {
680                 usleep_range(500, 1000);
681                 qxl_queue_garbage_collect(qdev, true);
682         }
683
684         return 0;
685 }