drm: add cap bit to denote if dumb ioctl is available or not.

This allows libkms to make an easier decision.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index d6de9d042b76..7f6912a16761 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -275,6 +275,14 @@ int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
         struct drm_get_cap *req = data;
 
         req->value = 0;
+        switch (req->capability) {
+        case DRM_CAP_DUMB_BUFFER:
+                if (dev->driver->dumb_create)
+                        req->value = 1;
+                break;
+        default:
+                return -EINVAL;
+        }
         return 0;
 }