[PATCH v2] drm: Check in setcrtc if the primary plane supports the fb pixel format

[Laurent Pinchart]

Drivers implementing the universal planes API report the list of
supported pixel formats for the primary plane. Make sure the fb passed
to the setcrtc ioctl is compatible.

Drivers not implementing the universal planes API will have no format
reported for the primary plane, skip the check in that case.

Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
 drivers/gpu/drm/drm_crtc.c         | 17 +++++++++++++++++
 drivers/gpu/drm/drm_plane_helper.c |  5 +++++
 include/drm/drm_crtc.h             |  2 ++
 3 files changed, 24 insertions(+)

Changes since v1:

- Add drm_plane.format_default field

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index d794bcf..5c49cb3 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -2807,6 +2807,23 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
 
 		drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
 
+		/*
+		 * Check whether the primary plane supports the fb pixel format.
+		 * Drivers not implementing the universal planes API use a
+		 * default formats list provided by the DRM core which doesn't
+		 * match real hardware capabilities. Skip the check in that
+		 * case.
+		 */
+		if (!crtc->primary->format_default) {
+			ret = drm_plane_check_pixel_format(crtc->primary,
+							   fb->pixel_format);
+			if (ret) {
+				DRM_DEBUG_KMS("Invalid pixel format %s\n",
+					drm_get_format_name(fb->pixel_format));
+				goto out;
+			}
+		}
+
 		ret = drm_crtc_check_viewport(crtc, crtc_req->x, crtc_req->y,
 					      mode, fb);
 		if (ret)
diff --git a/drivers/gpu/drm/drm_plane_helper.c b/drivers/gpu/drm/drm_plane_helper.c
index 813a066..a56a429 100644
--- a/drivers/gpu/drm/drm_plane_helper.c
+++ b/drivers/gpu/drm/drm_plane_helper.c
@@ -371,6 +371,11 @@ struct drm_plane *drm_primary_helper_create_plane(struct drm_device *dev,
 	if (formats == NULL) {
 		formats = safe_modeset_formats;
 		num_formats = ARRAY_SIZE(safe_modeset_formats);
+		/*
+		 * Remove the format_default field from drm_plane when dropping
+		 * this helper.
+		 */
+		primary->format_default = true;
 	}
 
 	/* possible_crtc's will be filled in later by crtc_init */
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index da83d39..adc9ea5 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -830,6 +830,7 @@ enum drm_plane_type {
  * @possible_crtcs: pipes this plane can be bound to
  * @format_types: array of formats supported by this plane
  * @format_count: number of formats supported
+ * @format_default: driver hasn't supplied supported formats for the plane
  * @crtc: currently bound CRTC
  * @fb: currently bound fb
  * @old_fb: Temporary tracking of the old fb while a modeset is ongoing. Used by
@@ -850,6 +851,7 @@ struct drm_plane {
 	uint32_t possible_crtcs;
 	uint32_t *format_types;
 	uint32_t format_count;
+	bool format_default;
 
 	struct drm_crtc *crtc;
 	struct drm_framebuffer *fb;
-- 
Regards,

Laurent Pinchart