On Wed, Feb 19, 2025 at 02:47:23PM +0530, Arun R Murthy wrote:
> There exists a property IN_FORMATS which exposes the plane supported
> modifiers/formats to the user. In some platforms when asynchronous flip
> are used all of modifiers/formats mentioned in IN_FORMATS are not
> supported. This patch adds a new plane property IN_FORMATS_ASYNC to
> expose the async flip supported modifiers/formats so that user can use
> this information ahead and do flip with unsupported
> formats/modifiers. This will save flip failures.
> Add a new function pointer similar to format_mod_supported specifically
> for asynchronous flip.
>
> v2: Remove async variable from drm_plane (Ville)
> v3: Add new function pointer for async (Ville)
> v5: Typo corrected in commit message & some correction in the kernel
> documentation. (Chaitanya)
>
> Signed-off-by: Arun R Murthy <arun.r.mur...@intel.com>
> Reviewed-by: Chaitanya Kumar Borah <chaitanya.kumar.bo...@intel.com>
> Tested-by: Naveen Kumar <naveen1.ku...@intel.com>
> ---
> drivers/gpu/drm/drm_mode_config.c | 7 +++++++
> drivers/gpu/drm/drm_plane.c | 8 ++++++++
> include/drm/drm_mode_config.h | 6 ++++++
> include/drm/drm_plane.h | 17 +++++++++++++++++
> 4 files changed, 38 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_mode_config.c
> b/drivers/gpu/drm/drm_mode_config.c
> index
> 8642a2fb25a90116dab975aa0ab6b51deafb4b96..dbbef20753f834a85ae9ded748cff2b3f0e85043
> 100644
> --- a/drivers/gpu/drm/drm_mode_config.c
> +++ b/drivers/gpu/drm/drm_mode_config.c
> @@ -388,6 +388,13 @@ static int drm_mode_create_standard_properties(struct
> drm_device *dev)
> return -ENOMEM;
> dev->mode_config.size_hints_property = prop;
>
> + prop = drm_property_create(dev,
> + DRM_MODE_PROP_IMMUTABLE | DRM_MODE_PROP_BLOB,
> + "IN_FORMATS_ASYNC", 0);
> + if (!prop)
> + return -ENOMEM;
> + dev->mode_config.async_modifiers_property = prop;
Please put it next to the other blob.
> +
> return 0;
> }
>
> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
> index
> a28b22fdd7a41aca82d097d42237851da9a0a79b..fe181c1002171acc68d3054c2d178f9b9f501fe2
> 100644
> --- a/drivers/gpu/drm/drm_plane.c
> +++ b/drivers/gpu/drm/drm_plane.c
> @@ -141,6 +141,14 @@
> * various bugs in this area with inconsistencies between the capability
> * flag and per-plane properties.
> *
> + * IN_FORMATS_ASYNC:
> + * Blob property which contains the set of buffer format and modifier
> + * pairs supported by this plane for asynchronous flips. The blob is a
> struct
> + * drm_format_modifier_blob. Userspace cannot change this property. This
> is an
> + * optional property and if not present then user should expect a
> failure in
> + * atomic ioctl when the modifier/format is not supported by that plane
> under
> + * asynchronous flip.
> + *
> * SIZE_HINTS:
> * Blob property which contains the set of recommended plane size
> * which can used for simple "cursor like" use cases (eg. no scaling).
> diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
> index
> 271765e2e9f2da62aaf0d258828ef4196e14822e..0c116d6dfd277262b1a4c0f097fce2d719f43844
> 100644
> --- a/include/drm/drm_mode_config.h
> +++ b/include/drm/drm_mode_config.h
> @@ -936,6 +936,12 @@ struct drm_mode_config {
> */
> struct drm_property *modifiers_property;
>
> + /**
> + * @async_modifiers_property: Plane property to list support
> modifier/format
> + * combination for asynchronous flips.
> + */
> + struct drm_property *async_modifiers_property;
> +
> /**
> * @size_hints_property: Plane SIZE_HINTS property.
> */
> diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
> index
> dd718c62ac31bf16606f3ee9f025a5b171cd1e67..4393a0e9edf91ccfd78ef62b168b9313187c1a81
> 100644
> --- a/include/drm/drm_plane.h
> +++ b/include/drm/drm_plane.h
> @@ -549,6 +549,23 @@ struct drm_plane_funcs {
> */
> bool (*format_mod_supported)(struct drm_plane *plane, uint32_t format,
> uint64_t modifier);
> + /**
> + * @format_mod_supported_async:
> + *
> + * This optional hook is used for the DRM to determine if for
> + * asynchronous flip the given format/modifier combination is valid for
> + * the plane. This allows the DRM to generate the correct format
> + * bitmask (which formats apply to which modifier), and to validate
> + * modifiers at atomic_check time.
> + *
> + * Returns:
> + *
> + * True if the given modifier is valid for that format on the plane.
> + * False otherwise.
> + */
> + bool (*format_mod_supported_async)(struct drm_plane *plane,
> + uint32_t format, uint64_t modifier);
> +
> };
>
> /**
>
> --
> 2.25.1
--
Ville Syrjälä
Intel
