drm: Clarify the role of plane_state argument to drm_simple update().

Like the atomic update hook it's wrapping, the plane_state is the old
one, and the new one is in plane->state.  Both msxfb and tinydrm use
it correctly, but I mistook it for the new state in pl111 due to its
naming.

Signed-off-by: Eric Anholt <eric@anholt.net>
Link: http://patchwork.freedesktop.org/patch/msgid/20170320233615.5242-3-eric@anholt.net
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

2 files changed, 3 insertions, 3 deletions

diff --git a/drivers/gpu/drm/drm_simple_kms_helper.c b/drivers/gpu/drm/drm_simple_kms_helper.c
index 16789faa9291..e084f9f8ca66 100644
--- a/drivers/gpu/drm/drm_simple_kms_helper.c
+++ b/drivers/gpu/drm/drm_simple_kms_helper.c
@@ -114,7 +114,7 @@ static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
 }
 
 static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
-                                        struct drm_plane_state *pstate)
+                                        struct drm_plane_state *old_pstate)
 {
         struct drm_simple_display_pipe *pipe;
 
@@ -122,7 +122,7 @@ static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
         if (!pipe->funcs || !pipe->funcs->update)
                 return;
 
-        pipe->funcs->update(pipe, pstate);
+        pipe->funcs->update(pipe, old_pstate);
 }
 
 static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
diff --git a/include/drm/drm_simple_kms_helper.h b/include/drm/drm_simple_kms_helper.h
index fffbb95a0915..2d36538e4a17 100644
--- a/include/drm/drm_simple_kms_helper.h
+++ b/include/drm/drm_simple_kms_helper.h
@@ -72,7 +72,7 @@ struct drm_simple_display_pipe_funcs {
          * the hardware lacks vblank support entirely.
          */
         void (*update)(struct drm_simple_display_pipe *pipe,
-                       struct drm_plane_state *plane_state);
+                       struct drm_plane_state *old_plane_state);
 
         /**
          * @prepare_fb: