drm/atomic-helpers: make mode_set hooks optional

With runtime PM the hw might still be off while doing the ->mode_set
callbacks - runtime PM get/put should only happen in the
enable/disable hooks to properly support DPMS. Which essentially makes
these callbacks useless for drivers support runtime PM, so make them
optional. Again motivated by discussions with Laurent.

Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/drm/drm_crtc_helper.h b/include/drm/drm_crtc_helper.h
index c250a22b39ab..92d5135b55d2 100644
--- a/include/drm/drm_crtc_helper.h
+++ b/include/drm/drm_crtc_helper.h
@@ -89,6 +89,7 @@ struct drm_crtc_helper_funcs {
         int (*mode_set)(struct drm_crtc *crtc, struct drm_display_mode *mode,
                         struct drm_display_mode *adjusted_mode, int x, int y,
                         struct drm_framebuffer *old_fb);
+        /* Actually set the mode for atomic helpers, optional */
         void (*mode_set_nofb)(struct drm_crtc *crtc);
 
         /* Move the crtc on the current fb to the given position *optional* */
@@ -119,7 +120,7 @@ struct drm_crtc_helper_funcs {
  * @mode_fixup: try to fixup proposed mode for this connector
  * @prepare: part of the disable sequence, called before the CRTC modeset
  * @commit: called after the CRTC modeset
- * @mode_set: set this mode
+ * @mode_set: set this mode, optional for atomic helpers
  * @get_crtc: return CRTC that the encoder is currently attached to
  * @detect: connection status detection
  * @disable: disable encoder when not in use (overrides DPMS off)