drm: Add dev->vblank_disable_immediate flag

Add a flag to drm_device which will cause the vblank code to bypass the
disable timer and always disable the vblank interrupt immediately when
the last reference is dropped.

v2: Add some notes about the flag to the kernel doc

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>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 24b32d453c60..17a5c10474bd 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1074,6 +1074,16 @@ struct drm_device {
 	 */
 	bool vblank_disable_allowed;
 
+	/*
+	 * If true, vblank interrupt will be disabled immediately when the
+	 * refcount drops to zero, as opposed to via the vblank disable
+	 * timer.
+	 * This can be set to true it the hardware has a working vblank
+	 * counter and the driver uses drm_vblank_on() and drm_vblank_off()
+	 * appropriately.
+	 */
+	bool vblank_disable_immediate;
+
 	/* array of size num_crtcs */
 	struct drm_vblank_crtc *vblank;