drm: Update obsolete information from {enable/disable}_vblank hooks.
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@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1464795342-32297-1-git-send-email-Liviu.Dudau@arm.com
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index c5d2950..0051828 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -430,7 +430,7 @@
*
* 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.
*
@@ -448,8 +448,8 @@
* @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
@@ -463,8 +463,8 @@
* @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);