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.murthy@intel.com>
Acked-by: Xaver Hugl <xaver.hugl@kde.org>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Naveen Kumar <naveen1.kumar@intel.com>
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://lore.kernel.org/r/20250407-asyn-v13-1-b93ef83076c5@intel.com

diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
index 8642a2fb25a90116dab975aa0ab6b51deafb4b96..b4239fd04e9da4d4b5cfccdef1d3dde9556f322d 100644 (file)
--- 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..fe181c1002171acc68d3054c2d178f9b9f501fe2 100644 (file)
--- 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 4b8f0370b79bf573a03cffaf5bcb776010b88f31..9e524b51a001863772c08fcd51df1caa9e183c99 100644 (file)
--- 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..01479dd94e76a8389a0c9e9d6744400aa2291064 100644 (file)
--- 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);
+
 };
 
 /**