> -----Original Message-----
> From: Murthy, Arun R <arun.r.mur...@intel.com>
> Sent: Wednesday, March 12, 2025 6:39 PM
> To: dri-de...@lists.freedesktop.org; intel-gfx@lists.freedesktop.org; intel-
> x...@lists.freedesktop.org
> Cc: Borah, Chaitanya Kumar <chaitanya.kumar.bo...@intel.com>;
> 20250219093211.4059187-1-arun.r.mur...@intel.com;
> 20250311085422.2573860-1-santhosh.reddy.gudd...@intel.com; Murthy,
> Arun R <arun.r.mur...@intel.com>; Kumar, Naveen1
> <naveen1.ku...@intel.com>
> Subject: [PATCH v8 1/3] drm/plane: Add new plane property
> IN_FORMATS_ASYNC
>
> 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)
> v7: Place IN_FORMATS_ASYNC next to IN_FORMATS (Ville)
> v8: replace uint32_t with u32 and uint64_t with u64 (Chaitanya)
>
> Signed-off-by: Arun R Murthy <arun.r.mur...@intel.com>
> Tested-by: Naveen Kumar <naveen1.ku...@intel.com>
> ---
> drivers/gpu/drm/drm_mode_config.c | 7 +++++++
> drivers/gpu/drm/drm_plane.c | 12 ++++++++++--
> include/drm/drm_mode_config.h | 6 ++++++
> include/drm/drm_plane.h | 17 +++++++++++++++++
> 4 files changed, 40 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_mode_config.c
> b/drivers/gpu/drm/drm_mode_config.c
> index
> 8642a2fb25a90116dab975aa0ab6b51deafb4b96..b4239fd04e9da4d4b5cfc
> cdef1d3dde9556f322d 100644
> --- a/drivers/gpu/drm/drm_mode_config.c
> +++ b/drivers/gpu/drm/drm_mode_config.c
> @@ -381,6 +381,13 @@ static int
> drm_mode_create_standard_properties(struct drm_device *dev)
> return -ENOMEM;
> dev->mode_config.modifiers_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;
> +
> prop = drm_property_create(dev,
> DRM_MODE_PROP_IMMUTABLE |
> DRM_MODE_PROP_BLOB,
> "SIZE_HINTS", 0);
> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
> index
> a28b22fdd7a41aca82d097d42237851da9a0a79b..110838c3e5920835e08
> 75e57e6e479bcab7c8733 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).
> @@ -197,7 +205,7 @@ static int create_in_format_blob(struct drm_device
> *dev, struct drm_plane *plane
> formats_size = sizeof(__u32) * plane->format_count;
> if (WARN_ON(!formats_size)) {
> /* 0 formats are never expected */
> - return 0;
> + return ERR_PTR(0);
...
> }
>
> modifiers_size =
> @@ -213,7 +221,7 @@ static int create_in_format_blob(struct drm_device
> *dev, struct drm_plane *plane
>
> blob = drm_property_create_blob(dev, blob_size, NULL);
> if (IS_ERR(blob))
> - return -1;
> + return ERR_PTR(-1);
Were we seeing any warnings because of this?
If at all needed, it should be part of the second patch [1]
Regards
Chaitanya
[1] https://patchwork.freedesktop.org/patch/642713/?series=140935&rev=8
>
> blob_data = blob->data;
> blob_data->version = FORMAT_BLOB_CURRENT; diff --git
> a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
> index
> 271765e2e9f2da62aaf0d258828ef4196e14822e..0c116d6dfd277262b1a4c
> 0f097fce2d719f43844 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..01479dd94e76a8389a0c
> 9e9d6744400aa2291064 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,
> + u32 format, u64 modifier);
> +
> };
>
> /**
>
> --
> 2.25.1
