On Tue, Aug 06, 2024 at 10:52:59AM GMT, André Almeida wrote:
> Currently, DRM atomic uAPI allows only primary planes to be flipped
> asynchronously. However, each driver might be able to perform async
> flips in other different plane types. To enable drivers to set their own
> restrictions on which type of plane they can or cannot flip, use the
> existing atomic_async_check() from struct drm_plane_helper_funcs to
> enhance this flexibility, thus allowing different plane types to be able
> to do async flips as well.
>
> In order to prevent regressions and such, we keep the current policy: we
> skip the driver check for the primary plane, because it is always
> allowed to do async flips on it.
Unfortunately this needs to be rebased on top of 929725bd7eb4
("drm/atomic: allow no-op FB_ID updates for async flips"), but the
approach looks good to me and it fits the existing API.
>
> Signed-off-by: André Almeida <andrealm...@igalia.com>
> ---
> drivers/gpu/drm/drm_atomic_uapi.c | 23 +++++++++++++++++------
> 1 file changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic_uapi.c
> b/drivers/gpu/drm/drm_atomic_uapi.c
> index fc16fddee5c5..8568c2428670 100644
> --- a/drivers/gpu/drm/drm_atomic_uapi.c
> +++ b/drivers/gpu/drm/drm_atomic_uapi.c
> @@ -27,8 +27,9 @@
> * Daniel Vetter <daniel.vet...@ffwll.ch>
> */
>
> -#include <drm/drm_atomic_uapi.h>
> #include <drm/drm_atomic.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_atomic_uapi.h>
> #include <drm/drm_framebuffer.h>
> #include <drm/drm_print.h>
> #include <drm/drm_drv.h>
> @@ -1059,6 +1060,7 @@ int drm_atomic_set_property(struct drm_atomic_state
> *state,
> struct drm_plane *plane = obj_to_plane(obj);
> struct drm_plane_state *plane_state;
> struct drm_mode_config *config = &plane->dev->mode_config;
> + const struct drm_plane_helper_funcs *plane_funcs =
> plane->helper_private;
>
> plane_state = drm_atomic_get_plane_state(state, plane);
> if (IS_ERR(plane_state)) {
> @@ -1073,11 +1075,20 @@ int drm_atomic_set_property(struct drm_atomic_state
> *state,
> break;
> }
>
> - if (async_flip && plane_state->plane->type !=
> DRM_PLANE_TYPE_PRIMARY) {
> - drm_dbg_atomic(prop->dev,
> - "[OBJECT:%d] Only primary planes can be
> changed during async flip\n",
> - obj->id);
> - ret = -EINVAL;
> + if (async_flip) {
> + /* we always allow primary planes */
> + if (plane->type != DRM_PLANE_TYPE_PRIMARY) {
> + ret = -EINVAL;
> +
> + if (plane_funcs &&
> plane_funcs->atomic_async_check)
> + ret =
> plane_funcs->atomic_async_check(plane, state);
> +
> + if (ret) {
> + drm_dbg_atomic(prop->dev,
> + "[PLANE:%d] does not
> support async flips\n",
> + obj->id);
> + }
> + }
> break;
> }
>
> --
> 2.46.0
>
--
With best wishes
Dmitry
