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drm: Have the vblank counter account for the time between vblank irq disable and drm_vblank_off()

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If the vblank irq has already been disabled (via the disable timer) when
we call drm_vblank_off() sample the counter and timestamp one last time.
This will make the sure that the user space visible counter will account
for time between vblank irq disable and drm_vblank_off().

Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Ville Syrjälä 2014-08-06 14:49:48 +03:00 committed by Daniel Vetter
parent 13b030af54
commit 812e7465a7
1 changed files with 13 additions and 0 deletions
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13
drivers/gpu/drm/drm_irq.c
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@ -140,6 +140,19 @@ static void vblank_disable_and_save(struct drm_device *dev, int crtc)
*/
spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
/*
* If the vblank interrupt was already disbled update the count
* and timestamp to maintain the appearance that the counter
* has been ticking all along until this time. This makes the
* count account for the entire time between drm_vblank_on() and
* drm_vblank_off().
*/
if (!dev->vblank[crtc].enabled) {
drm_update_vblank_count(dev, crtc);
spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
return;
}
dev->driver->disable_vblank(dev, crtc);
dev->vblank[crtc].enabled = false;