diff options
Diffstat (limited to 'drivers/gpu/drm/drm_irq.c')
| -rw-r--r-- | drivers/gpu/drm/drm_irq.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 124402270568..aa23b9833588 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -1561,6 +1561,17 @@ err_put: return ret; } +static bool drm_wait_vblank_is_query(union drm_wait_vblank *vblwait) +{ + if (vblwait->request.sequence) + return false; + + return _DRM_VBLANK_RELATIVE == + (vblwait->request.type & (_DRM_VBLANK_TYPES_MASK | + _DRM_VBLANK_EVENT | + _DRM_VBLANK_NEXTONMISS)); +} + /* * Wait for VBLANK. * @@ -1610,6 +1621,21 @@ int drm_wait_vblank(struct drm_device *dev, void *data, vblank = &dev->vblank[pipe]; + /* If the counter is currently enabled and accurate, short-circuit + * queries to return the cached timestamp of the last vblank. + */ + if (dev->vblank_disable_immediate && + drm_wait_vblank_is_query(vblwait) && + READ_ONCE(vblank->enabled)) { + struct timeval now; + + vblwait->reply.sequence = + drm_vblank_count_and_time(dev, pipe, &now); + vblwait->reply.tval_sec = now.tv_sec; + vblwait->reply.tval_usec = now.tv_usec; + return 0; + } + ret = drm_vblank_get(dev, pipe); if (ret) { DRM_DEBUG("crtc %d failed to acquire vblank counter, %d\n", pipe, ret); |