[Intel-gfx] [PATCH 1/3] drm: Make sure at least one plane supports the fb format

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

To make life easier for drivers, let's have the core check that the
requested pixel format is supported by at least one plane when creating
a new framebuffer.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/drm_framebuffer.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
index c0530a1af5e3..155b21e579c4 100644
--- a/drivers/gpu/drm/drm_framebuffer.c
+++ b/drivers/gpu/drm/drm_framebuffer.c
@@ -152,6 +152,23 @@ static int fb_plane_height(int height,
 	return DIV_ROUND_UP(height, format->vsub);
 }
 
+static bool planes_have_format(struct drm_device *dev, u32 format)
+{
+	struct drm_plane *plane;
+
+	/* TODO: maybe maintain a device level format list? */
+	drm_for_each_plane(plane, dev) {
+		int i;
+
+		for (i = 0; i < plane->format_count; i++) {
+			if (plane->format_types[i] == format)
+				return true;
+		}
+	}
+
+	return false;
+}
+
 static int framebuffer_check(struct drm_device *dev,
 			     const struct drm_mode_fb_cmd2 *r)
 {
@@ -168,6 +185,15 @@ static int framebuffer_check(struct drm_device *dev,
 		return -EINVAL;
 	}
 
+	if (!planes_have_format(dev, r->pixel_format)) {
+		struct drm_format_name_buf format_name;
+
+		DRM_DEBUG_KMS("unsupported framebuffer format %s\n",
+			      drm_get_format_name(r->pixel_format,
+						  &format_name));
+		return -EINVAL;
+	}
+
 	/* now let the driver pick its own format info */
 	info = drm_get_format_info(dev, r);
 
-- 
2.16.1