Since commit 4dfd64862ff8 ("drm: Use vblank timestamps to guesstimate how many vblanks were missed"), the DRM framework can cope with devices that don't have a hardware counter for vsync events without having to keep the vsync interrupts enabled all the time. Drivers handling such hardware should use drm_vblank_no_hw_counter() function for their ->get_vblank_counter hook. Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Signed-off-by: Liviu Dudau <Liviu.Dudau@xxxxxxx> --- include/drm/drmP.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 84f1a8e..d486118 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -434,7 +434,7 @@ struct drm_driver { * * Driver callback for fetching a raw hardware vblank counter for @crtc. * If a device doesn't have a hardware counter, the driver can simply - * return the value of drm_vblank_count. The DRM core will account for + * use drm_vblank_no_hw_counter() function. The DRM core will account for * missed vblank events while interrupts where disabled based on system * timestamps. * @@ -452,8 +452,8 @@ struct drm_driver { * @pipe: which irq to enable * * Enable vblank interrupts for @crtc. If the device doesn't have - * a hardware vblank counter, this routine should be a no-op, since - * interrupts will have to stay on to keep the count accurate. + * a hardware vblank counter, the driver should use the + * drm_vblank_no_hw_counter() function that keeps a virtual counter. * * RETURNS * Zero on success, appropriate errno if the given @crtc's vblank @@ -467,8 +467,8 @@ struct drm_driver { * @pipe: which irq to enable * * Disable vblank interrupts for @crtc. If the device doesn't have - * a hardware vblank counter, this routine should be a no-op, since - * interrupts will have to stay on to keep the count accurate. + * a hardware vblank counter, the driver should use the + * drm_vblank_no_hw_counter() function that keeps a virtual counter. */ void (*disable_vblank) (struct drm_device *dev, unsigned int pipe); -- 2.8.2 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel