drm/vblank: Allow dynamic per-crtc max_vblank_count

[platform/kernel/linux-rpi.git] / include / drm / drm_device.h

diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
index f9c6e0e..fa117e1 100644 (file)
--- a/include/drm/drm_device.h
+++ b/include/drm/drm_device.h
@@ -174,7 +174,13 @@ struct drm_device {
         * races and imprecision over longer time periods, hence exposing a
         * hardware vblank counter is always recommended.
         *
-        * If non-zeor, &drm_crtc_funcs.get_vblank_counter must be set.
+        * This is the statically configured device wide maximum. The driver
+        * can instead choose to use a runtime configurable per-crtc value
+        * &drm_vblank_crtc.max_vblank_count, in which case @max_vblank_count
+        * must be left at zero. See drm_crtc_set_max_vblank_count() on how
+        * to use the per-crtc value.
+        *
+        * If non-zero, &drm_crtc_funcs.get_vblank_counter must be set.
         */
        u32 max_vblank_count;           /**< size of vblank counter register */