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 <[email protected]>
Acked-by: Xaver Hugl <[email protected]>
Acked-by: Harry Wentland <[email protected]>
Reviewed-by: Chaitanya Kumar Borah <[email protected]>
Reviewed-by: Ville Syrjälä <[email protected]>
Tested-by: Naveen Kumar <[email protected]>
Signed-off-by: Suraj Kandpal <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: armurthy

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);

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).

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.
 	 */

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);
+
 };
 
 /**