5 files changed, 17 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index 2300ab1a2a77..cf85155da2a0 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -277,6 +277,12 @@ int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
         case DRM_CAP_VBLANK_HIGH_CRTC:
                 req->value = 1;
                 break;
+        case DRM_CAP_DUMB_PREFERRED_DEPTH:
+                req->value = dev->mode_config.preferred_depth;
+                break;
+        case DRM_CAP_DUMB_PREFER_SHADOW:
+                req->value = dev->mode_config.prefer_shadow;
+                break;
         default:
                 return -EINVAL;
         }
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index dfa67449827a..0a8a640d36ef 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9089,6 +9089,9 @@ void intel_modeset_init(struct drm_device *dev)
         dev->mode_config.min_width = 0;
         dev->mode_config.min_height = 0;
 
+        dev->mode_config.preferred_depth = 24;
+        dev->mode_config.prefer_shadow = 1;
+
         dev->mode_config.funcs = (void *)&intel_mode_funcs;
 
         intel_init_quirks(dev);
diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index 5515f1054b29..7cb062daa71e 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -1240,6 +1240,9 @@ int radeon_modeset_init(struct radeon_device *rdev)
                 rdev->ddev->mode_config.max_height = 4096;
         }
 
+        rdev->ddev->mode_config.preferred_depth = 24;
+        rdev->ddev->mode_config.prefer_shadow = 1;
+
         rdev->ddev->mode_config.fb_base = rdev->mc.aper_base;
 
         ret = radeon_modeset_create_props(rdev);
diff --git a/include/drm/drm.h b/include/drm/drm.h
index 49d94ede2ec2..34a7b89fd006 100644
--- a/include/drm/drm.h
+++ b/include/drm/drm.h
@@ -761,6 +761,8 @@ struct drm_event_vblank {
 
 #define DRM_CAP_DUMB_BUFFER 0x1
 #define DRM_CAP_VBLANK_HIGH_CRTC 0x2
+#define DRM_CAP_DUMB_PREFERRED_DEPTH 0x3
+#define DRM_CAP_DUMB_PREFER_SHADOW 0x4
 
 /* typedef area */
 #ifndef __KERNEL__
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 823531454799..2a0872cac333 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -796,6 +796,9 @@ struct drm_mode_config {
         struct drm_property *scaling_mode_property;
         struct drm_property *dithering_mode_property;
         struct drm_property *dirty_info_property;
+
+        /* dumb ioctl parameters */
+        uint32_t preferred_depth, prefer_shadow;
 };
 
 #define obj_to_crtc(x) container_of(x, struct drm_crtc, base)