Re: [PATCH 10/10] drm: Use state helper instead of the plane state pointer

Laurent Pinchart
2021-01-15T21:20:48Z

Hi Maxime,

Thank you for the patch.

On Fri, Jan 15, 2021 at 01:57:02PM +0100, Maxime Ripard wrote:
> Many drivers reference the plane->state pointer in order to get the
> current plane state in their atomic_update or atomic_disable hooks,

Please don't use the word "current", it's ambiguous. Do you mean old
state or new state ?

> which would be the new plane state in the global atomic state since
> _swap_state happened when those hooks are run.

Is this relevant ? drm_atomic_helper_swap_state() doesn't change the
old_state and new_state pointers in drm_atomic_state as far as I can
tell.

> 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/...>
>
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> ---

[snip]

> drivers/gpu/drm/omapdrm/omap_plane.c | 6 ++++--
> drivers/gpu/drm/rcar-du/rcar_du_plane.c | 3 ++-
> drivers/gpu/drm/rcar-du/rcar_du_vsp.c | 3 ++-
> drivers/gpu/drm/xlnx/zynqmp_disp.c | 3 ++-

[snip]

> diff --git a/drivers/gpu/drm/omapdrm/omap_plane.c b/drivers/gpu/drm/omapdrm/omap_plane.c
> index cd8cf7c786b5..021a94de84a1 100644
> --- a/drivers/gpu/drm/omapdrm/omap_plane.c
> +++ b/drivers/gpu/drm/omapdrm/omap_plane.c
> @@ -44,7 +44,8 @@ static void omap_plane_atomic_update(struct drm_plane *plane,
> {
> struct omap_drm_private *priv = plane->dev->dev_private;
> struct omap_plane *omap_plane = to_omap_plane(plane);
> - struct drm_plane_state *new_state = plane->state;

This seems to imply that you're interested in the new state.

> + struct drm_plane_state *new_state = drm_atomic_get_new_plane_state(state,
> + plane);

Does this really make things more obvious ?

> struct omap_overlay_info info;
> int ret;
>
> @@ -89,7 +90,8 @@ static void omap_plane_atomic_update(struct drm_plane *plane,
> static void omap_plane_atomic_disable(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 omap_drm_private *priv = plane->dev->dev_private;
> struct omap_plane *omap_plane = to_omap_plane(plane);
>

[snip]

--
Regards,

Laurent Pinchart