[RFC PATCH v4 2/3] drm: add support modifiers for drivers whose planes only support linear layout

From: Tomohito Esaki
Date: Tue Jan 18 2022 - 03:37:34 EST


The LINEAR modifier is advertised as default if a driver doesn't specify
modifiers.

Signed-off-by: Tomohito Esaki <etom@xxxxxxxxxx>
---
drivers/gpu/drm/drm_plane.c | 15 ++++++++++++---
include/drm/drm_plane.h | 3 +++
2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
index deeec60a3315..5aa7e241971e 100644
--- a/drivers/gpu/drm/drm_plane.c
+++ b/drivers/gpu/drm/drm_plane.c
@@ -237,6 +237,10 @@ static int __drm_universal_plane_init(struct drm_device *dev,
const char *name, va_list ap)
{
struct drm_mode_config *config = &dev->mode_config;
+ const uint64_t default_modifiers[] = {
+ DRM_FORMAT_MOD_LINEAR,
+ DRM_FORMAT_MOD_INVALID
+ };
unsigned int format_modifier_count = 0;
int ret;

@@ -277,6 +281,11 @@ static int __drm_universal_plane_init(struct drm_device *dev,

while (*temp_modifiers++ != DRM_FORMAT_MOD_INVALID)
format_modifier_count++;
+ } else {
+ if (!dev->mode_config.fb_modifiers_not_supported) {
+ format_modifiers = default_modifiers;
+ format_modifier_count = 1;
+ }
}

/* autoset the cap and check for consistency across all planes */
@@ -341,7 +350,7 @@ static int __drm_universal_plane_init(struct drm_device *dev,
drm_object_attach_property(&plane->base, config->prop_src_h, 0);
}

- if (config->allow_fb_modifiers)
+ if (format_modifier_count)
create_in_format_blob(dev, plane);

return 0;
@@ -368,8 +377,8 @@ static int __drm_universal_plane_init(struct drm_device *dev,
* drm_universal_plane_init() to let the DRM managed resource infrastructure
* take care of cleanup and deallocation.
*
- * Drivers supporting modifiers must set @format_modifiers on all their planes,
- * even those that only support DRM_FORMAT_MOD_LINEAR.
+ * For drivers supporting modifiers, all planes will advertise
+ * DRM_FORMAT_MOD_LINEAR support, if @format_modifiers is not set.
*
* Returns:
* Zero on success, error code on failure.
diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
index 0c1102dc4d88..cad641b1f797 100644
--- a/include/drm/drm_plane.h
+++ b/include/drm/drm_plane.h
@@ -803,6 +803,9 @@ void *__drmm_universal_plane_alloc(struct drm_device *dev,
*
* The @drm_plane_funcs.destroy hook must be NULL.
*
+ * For drivers supporting modifiers, all planes will advertise
+ * DRM_FORMAT_MOD_LINEAR support, if @format_modifiers is not set.
+ *
* Returns:
* Pointer to new plane, or ERR_PTR on failure.
*/
--
2.25.1