drm: Use state helper instead of the plane state pointer

Many drivers reference the plane->state pointer in order to get the
current plane state in their atomic_update or atomic_disable hooks,
which would be the new plane state in the global atomic state since
_swap_state happened when those hooks are run.

Use the drm_atomic_get_new_plane_state helper to get that state to make it
more obvious.

This was made using the coccinelle script below:

@ plane_atomic_func @
identifier helpers;
identifier func;
@@

(
 static const struct drm_plane_helper_funcs helpers = {
 	...,
 	.atomic_disable = func,
	...,
 };
|
 static const struct drm_plane_helper_funcs helpers = {
 	...,
 	.atomic_update = func,
	...,
 };
)

@ adds_new_state @
identifier plane_atomic_func.func;
identifier plane, state;
identifier new_state;
@@

 func(struct drm_plane *plane, struct drm_atomic_state *state)
 {
 	...
-	struct drm_plane_state *new_state = plane->state;
+	struct drm_plane_state *new_state = drm_atomic_get_new_plane_state(state, plane);
	...
 }

@ include depends on adds_new_state @
@@

 #include <drm/drm_atomic.h>

@ no_include depends on !include && adds_new_state @
@@

+ #include <drm/drm_atomic.h>
  #include <drm/...>

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20210219120032.260676-1-maxime@cerno.tech

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/gpu/drm/qxl/qxl_display.c b/drivers/gpu/drm/qxl/qxl_display.c
index 72ef82a048ad..e09b5041b684 100644
--- a/drivers/gpu/drm/qxl/qxl_display.c
+++ b/drivers/gpu/drm/qxl/qxl_display.c
@@ -634,7 +634,8 @@ static void qxl_free_cursor(struct qxl_bo *cursor_bo)
 static void qxl_primary_atomic_update(struct drm_plane *plane,
 				      struct drm_atomic_state *state)
 {
-	struct drm_plane_state *new_state = plane->state;
+	struct drm_plane_state *new_state = drm_atomic_get_new_plane_state(state,
+									   plane);
 	struct qxl_device *qdev = to_qxl(plane->dev);
 	struct qxl_bo *bo = gem_to_qxl_bo(new_state->fb->obj[0]);
 	struct qxl_bo *primary;
@@ -687,7 +688,8 @@ static void qxl_cursor_atomic_update(struct drm_plane *plane,
 {
 	struct drm_plane_state *old_state = drm_atomic_get_old_plane_state(state,
 									   plane);
-	struct drm_plane_state *new_state = plane->state;
+	struct drm_plane_state *new_state = drm_atomic_get_new_plane_state(state,
+									   plane);
 	struct qxl_device *qdev = to_qxl(plane->dev);
 	struct drm_framebuffer *fb = new_state->fb;