Re: [PATCH v2 2/2] drm/amdgpu: Implement check_async_props for planes

Ville Syrjälä
2024-01-19T18:26:09Z

On Fri, Jan 19, 2024 at 03:12:35PM -0300, André Almeida wrote:
> AMD GPUs can do async flips with changes on more properties than just
> the FB ID, so implement a custom check_async_props for AMD planes.
>
> Allow amdgpu to do async flips with IN_FENCE_ID and FB_DAMAGE_CLIPS
> properties. For userspace to check if a driver support this two
> properties, the strategy for now is to use TEST_ONLY commits.
>
> Signed-off-by: André Almeida <andrealmeid@igalia.com>
> ---
> v2: Drop overlay plane option for now
>
> .../amd/display/amdgpu_dm/amdgpu_dm_plane.c | 29 +++++++++++++++++++
> 1 file changed, 29 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
> index 116121e647ca..7afe8c1b62d4 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
> @@ -25,6 +25,7 @@
> */
>
> #include <drm/drm_atomic_helper.h>
> +#include <drm/drm_atomic_uapi.h>
> #include <drm/drm_blend.h>
> #include <drm/drm_gem_atomic_helper.h>
> #include <drm/drm_plane_helper.h>
> @@ -1430,6 +1431,33 @@ static void amdgpu_dm_plane_drm_plane_destroy_state(struct drm_plane *plane,
> drm_atomic_helper_plane_destroy_state(plane, state);
> }
>
> +static int amdgpu_dm_plane_check_async_props(struct drm_property *prop,
> + struct drm_plane *plane,
> + struct drm_plane_state *plane_state,
> + struct drm_mode_object *obj,
> + u64 prop_value, u64 old_val)
> +{
> + struct drm_mode_config *config = &plane->dev->mode_config;
> + int ret;
> +
> + if (prop != config->prop_fb_id &&
> + prop != config->prop_in_fence_fd &&

IN_FENCE should just be allowed always.

> + prop != config->prop_fb_damage_clips) {

This seems a bit dubious to me. How is amdgpu using the damage
information during async flips?

> + ret = drm_atomic_plane_get_property(plane, plane_state,
> + prop, &old_val);
> + return drm_atomic_check_prop_changes(ret, old_val, prop_value, prop);
> + }
> +
> + if (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);
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> static const struct drm_plane_funcs dm_plane_funcs = {
> .update_plane = drm_atomic_helper_update_plane,
> .disable_plane = drm_atomic_helper_disable_plane,
> @@ -1438,6 +1466,7 @@ static const struct drm_plane_funcs dm_plane_funcs = {
> .atomic_duplicate_state = amdgpu_dm_plane_drm_plane_duplicate_state,
> .atomic_destroy_state = amdgpu_dm_plane_drm_plane_destroy_state,
> .format_mod_supported = amdgpu_dm_plane_format_mod_supported,
> + .check_async_props = amdgpu_dm_plane_check_async_props,
> };
>
> int amdgpu_dm_plane_init(struct amdgpu_display_manager *dm,
> --
> 2.43.0

--
Ville Syrjälä
Intel