From 82c8e025b577a4b9b87fbbc2a1c4dd401e3a2521 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 15 Mar 2017 20:40:26 +0000 Subject: [PATCH] drm: Skip the waitqueue setup for vblank queries MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Avoid adding to the waitqueue and reprobing the current vblank if the caller is only querying the current vblank sequence and timestamp, where we know that the wait would return immediately. v2: Add CRTC identifier to debug messages Signed-off-by: Chris Wilson Cc: Ville Syrjälä Cc: Daniel Vetter Cc: Michel Dänzer Cc: Laurent Pinchart Cc: Dave Airlie , Cc: Mario Kleiner Reviewed-by: Michel Dänzer Reviewed-and-tested-by: Mario Kleiner Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20170315204027.20160-2-chris@chris-wilson.co.uk --- drivers/gpu/drm/drm_irq.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index e64b05ea95ea..53a526c7b24d 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -1610,7 +1610,7 @@ int drm_wait_vblank(struct drm_device *dev, void *data, ret = drm_vblank_get(dev, pipe); if (ret) { - DRM_DEBUG("failed to acquire vblank counter, %d\n", ret); + DRM_DEBUG("crtc %d failed to acquire vblank counter, %d\n", pipe, ret); return ret; } seq = drm_vblank_count(dev, pipe); @@ -1638,13 +1638,15 @@ int drm_wait_vblank(struct drm_device *dev, void *data, return drm_queue_vblank_event(dev, pipe, vblwait, file_priv); } - DRM_DEBUG("waiting on vblank count %u, crtc %u\n", - vblwait->request.sequence, pipe); - DRM_WAIT_ON(ret, vblank->queue, 3 * HZ, - (((drm_vblank_count(dev, pipe) - - vblwait->request.sequence) <= (1 << 23)) || - !vblank->enabled || - !dev->irq_enabled)); + if (vblwait->request.sequence != seq) { + DRM_DEBUG("waiting on vblank count %u, crtc %u\n", + vblwait->request.sequence, pipe); + DRM_WAIT_ON(ret, vblank->queue, 3 * HZ, + (((drm_vblank_count(dev, pipe) - + vblwait->request.sequence) <= (1 << 23)) || + !vblank->enabled || + !dev->irq_enabled)); + } if (ret != -EINTR) { struct timeval now; @@ -1653,10 +1655,10 @@ int drm_wait_vblank(struct drm_device *dev, void *data, vblwait->reply.tval_sec = now.tv_sec; vblwait->reply.tval_usec = now.tv_usec; - DRM_DEBUG("returning %u to client\n", - vblwait->reply.sequence); + DRM_DEBUG("crtc %d returning %u to client\n", + pipe, vblwait->reply.sequence); } else { - DRM_DEBUG("vblank wait interrupted by signal\n"); + DRM_DEBUG("crtc %d vblank wait interrupted by signal\n", pipe); } done: -- 2.11.0