Re: [PATCH RFC v5 02/10] drm: Introduce solid fill DRM plane property

From: Jessica Zhang
Date: Mon Aug 07 2023 - 12:35:06 EST




On 8/4/2023 6:40 AM, Sebastian Wick wrote:
On Mon, Jul 31, 2023 at 6:01 AM Dmitry Baryshkov
<dmitry.baryshkov@xxxxxxxxxx> wrote:

On 28/07/2023 20:02, Jessica Zhang wrote:
Document and add support for solid_fill property to drm_plane. In
addition, add support for setting and getting the values for solid_fill.

To enable solid fill planes, userspace must assign a property blob to
the "solid_fill" plane property containing the following information:

struct drm_mode_solid_fill {
u32 version;
u32 r, g, b;
};

Signed-off-by: Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>
---
drivers/gpu/drm/drm_atomic_state_helper.c | 9 +++++
drivers/gpu/drm/drm_atomic_uapi.c | 55 +++++++++++++++++++++++++++++++
drivers/gpu/drm/drm_blend.c | 30 +++++++++++++++++
include/drm/drm_blend.h | 1 +
include/drm/drm_plane.h | 35 ++++++++++++++++++++
include/uapi/drm/drm_mode.h | 24 ++++++++++++++
6 files changed, 154 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
index 01638c51ce0a..86fb876efbe6 100644
--- a/drivers/gpu/drm/drm_atomic_state_helper.c
+++ b/drivers/gpu/drm/drm_atomic_state_helper.c
@@ -254,6 +254,11 @@ void __drm_atomic_helper_plane_state_reset(struct drm_plane_state *plane_state,
plane_state->pixel_blend_mode = DRM_MODE_BLEND_PREMULTI;
plane_state->pixel_source = DRM_PLANE_PIXEL_SOURCE_FB;

+ if (plane_state->solid_fill_blob) {
+ drm_property_blob_put(plane_state->solid_fill_blob);
+ plane_state->solid_fill_blob = NULL;
+ }
+
if (plane->color_encoding_property) {
if (!drm_object_property_get_default_value(&plane->base,
plane->color_encoding_property,
@@ -336,6 +341,9 @@ void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
if (state->fb)
drm_framebuffer_get(state->fb);

+ if (state->solid_fill_blob)
+ drm_property_blob_get(state->solid_fill_blob);
+
state->fence = NULL;
state->commit = NULL;
state->fb_damage_clips = NULL;
@@ -385,6 +393,7 @@ void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state)
drm_crtc_commit_put(state->commit);

drm_property_blob_put(state->fb_damage_clips);
+ drm_property_blob_put(state->solid_fill_blob);
}
EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);

diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index 454f980e16c9..039686c78c2a 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -316,6 +316,51 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
}
EXPORT_SYMBOL(drm_atomic_set_crtc_for_connector);

+static int drm_atomic_set_solid_fill_prop(struct drm_plane_state *state,
+ struct drm_property_blob *blob)
+{
+ int blob_version;
+
+ if (blob == state->solid_fill_blob)
+ return 0;
+
+ if (blob) {
+ struct drm_mode_solid_fill *user_info = (struct drm_mode_solid_fill *)blob->data;
+
+ if (blob->length != sizeof(struct drm_mode_solid_fill)) {
+ drm_dbg_atomic(state->plane->dev,
+ "[PLANE:%d:%s] bad solid fill blob length: %zu\n",
+ state->plane->base.id, state->plane->name,
+ blob->length);
+ return -EINVAL;
+ }
+
+ blob_version = user_info->version;

I remember that we had versioning for quite some time. However it stroke
me while reviewing that we do not a way to negotiate supported
SOLID_FILL versions. However as we now have support for different
pixel_source properties, maybe we can drop version completely. If at
some point a driver needs to support different kind of SOLID_FILL
property (consider v2), we can add new pixel source to the enum.

Agreed. Let's drop the versioning.

Acked.

Thanks,

Jessica Zhang



+
+ /* Add more versions if necessary */
+ if (blob_version == 1) {
+ state->solid_fill.r = user_info->r;
+ state->solid_fill.g = user_info->g;
+ state->solid_fill.b = user_info->b;
+ } else {
+ drm_dbg_atomic(state->plane->dev,
+ "[PLANE:%d:%s] unsupported solid fill version (version=%d)\n",
+ state->plane->base.id, state->plane->name,
+ blob_version);
+ return -EINVAL;
+ }
+ }
+
+ drm_property_blob_put(state->solid_fill_blob);
+
+ if (blob)
+ state->solid_fill_blob = drm_property_blob_get(blob);
+ else
+ state->solid_fill_blob = NULL;
+
+ return 0;
+}
+
static void set_out_fence_for_crtc(struct drm_atomic_state *state,
struct drm_crtc *crtc, s32 __user *fence_ptr)
{
@@ -546,6 +591,13 @@ static int drm_atomic_plane_set_property(struct drm_plane *plane,
state->src_h = val;
} else if (property == plane->pixel_source_property) {
state->pixel_source = val;
+ } else if (property == plane->solid_fill_property) {
+ struct drm_property_blob *solid_fill = drm_property_lookup_blob(dev, val);
+
+ ret = drm_atomic_set_solid_fill_prop(state, solid_fill);
+ drm_property_blob_put(solid_fill);
+
+ return ret;

Bonus point: dropping version from SOLID_FILL would allow us to use
drm_atomic_replace_property_blob_from_id() here.

} else if (property == plane->alpha_property) {
state->alpha = val;
} else if (property == plane->blend_mode_property) {
@@ -620,6 +672,9 @@ drm_atomic_plane_get_property(struct drm_plane *plane,
*val = state->src_h;
} else if (property == plane->pixel_source_property) {
*val = state->pixel_source;
+ } else if (property == plane->solid_fill_property) {
+ *val = state->solid_fill_blob ?
+ state->solid_fill_blob->base.id : 0;
} else if (property == plane->alpha_property) {
*val = state->alpha;
} else if (property == plane->blend_mode_property) {
diff --git a/drivers/gpu/drm/drm_blend.c b/drivers/gpu/drm/drm_blend.c
index c500310a3d09..c632dfcd8a9b 100644
--- a/drivers/gpu/drm/drm_blend.c
+++ b/drivers/gpu/drm/drm_blend.c
@@ -200,6 +200,10 @@
* "FB":
* Framebuffer source set by the "FB_ID" property.
*
+ * solid_fill:
+ * solid_fill is set up with drm_plane_create_solid_fill_property(). It
+ * contains pixel data that drivers can use to fill a plane.
+ *
* Note that all the property extensions described here apply either to the
* plane or the CRTC (e.g. for the background color, which currently is not
* exposed and assumed to be black).
@@ -700,3 +704,29 @@ int drm_plane_create_pixel_source_property(struct drm_plane *plane,
return 0;
}
EXPORT_SYMBOL(drm_plane_create_pixel_source_property);
+
+/**
+ * drm_plane_create_solid_fill_property - create a new solid_fill property
+ * @plane: drm plane
+ *
+ * This creates a new property blob that holds pixel data for solid fill planes.
+ * The property is exposed to userspace as a property blob called "solid_fill".
+ *
+ * For information on what the blob contains, see `drm_mode_solid_fill`.
+ */
+int drm_plane_create_solid_fill_property(struct drm_plane *plane)
+{
+ struct drm_property *prop;
+
+ prop = drm_property_create(plane->dev,
+ DRM_MODE_PROP_ATOMIC | DRM_MODE_PROP_BLOB,
+ "solid_fill", 0);
+ if (!prop)
+ return -ENOMEM;
+
+ drm_object_attach_property(&plane->base, prop, 0);
+ plane->solid_fill_property = prop;
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_plane_create_solid_fill_property);
diff --git a/include/drm/drm_blend.h b/include/drm/drm_blend.h
index 122bbfbaae33..e7158fbee389 100644
--- a/include/drm/drm_blend.h
+++ b/include/drm/drm_blend.h
@@ -60,4 +60,5 @@ int drm_plane_create_blend_mode_property(struct drm_plane *plane,
unsigned int supported_modes);
int drm_plane_create_pixel_source_property(struct drm_plane *plane,
unsigned long extra_sources);
+int drm_plane_create_solid_fill_property(struct drm_plane *plane);
#endif
diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
index 89508b4dea4a..abf1458fa099 100644
--- a/include/drm/drm_plane.h
+++ b/include/drm/drm_plane.h
@@ -46,6 +46,17 @@ enum drm_plane_pixel_source {
DRM_PLANE_PIXEL_SOURCE_MAX
};

+/**
+ * struct solid_fill_property - RGB values for solid fill plane
+ *
+ * Note: This is the V1 for this feature
+ */
+struct drm_solid_fill {
+ uint32_t r;
+ uint32_t g;
+ uint32_t b;
+};
+
/**
* struct drm_plane_state - mutable plane state
*
@@ -130,6 +141,23 @@ struct drm_plane_state {
*/
enum drm_plane_pixel_source pixel_source;

+ /**
+ * @solid_fill_blob:
+ *
+ * Blob containing relevant information for a solid fill plane
+ * including pixel format and data. See
+ * drm_plane_create_solid_fill_property() for more details.
+ */
+ struct drm_property_blob *solid_fill_blob;
+
+ /**
+ * @solid_fill:
+ *
+ * Pixel data for solid fill planes. See
+ * drm_plane_create_solid_fill_property() for more details.
+ */
+ struct drm_solid_fill solid_fill;
+
/**
* @alpha:
* Opacity of the plane with 0 as completely transparent and 0xffff as
@@ -720,6 +748,13 @@ struct drm_plane {
*/
struct drm_property *pixel_source_property;

+ /**
+ * @solid_fill_property:
+ * Optional solid_fill property for this plane. See
+ * drm_plane_create_solid_fill_property().
+ */
+ struct drm_property *solid_fill_property;
+
/**
* @alpha_property:
* Optional alpha property for this plane. See
diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
index 43691058d28f..53c8efa5ad7f 100644
--- a/include/uapi/drm/drm_mode.h
+++ b/include/uapi/drm/drm_mode.h
@@ -259,6 +259,30 @@ struct drm_mode_modeinfo {
char name[DRM_DISPLAY_MODE_LEN];
};

+/**
+ * struct drm_mode_solid_fill - User info for solid fill planes
+ *
+ * This is the userspace API solid fill information structure.
+ *
+ * Userspace can enable solid fill planes by assigning the plane "solid_fill"
+ * property to a blob containing a single drm_mode_solid_fill struct populated with an RGB323232
+ * color and setting the pixel source to "SOLID_FILL".
+ *
+ * For information on the plane property, see drm_plane_create_solid_fill_property()
+ *
+ * @version: Version of the blob. Currently, there is only support for version == 1
+ * @r: Red color value of single pixel
+ * @g: Green color value of single pixel
+ * @b: Blue color value of single pixel
+ */
+struct drm_mode_solid_fill {
+ __u32 version;
+ __u32 r;
+ __u32 g;
+ __u32 b;
+};
+
+
struct drm_mode_card_res {
__u64 fb_id_ptr;
__u64 crtc_id_ptr;


--
With best wishes
Dmitry