drm/<drivers>: Unified handling of unimplemented fb->create_handle

Some drivers don't have real ->create_handle callbacks.

- cirrus/ast/mga200: Returns either 0 or -EINVAL.

- udl: Didn't even bother with a callback, leading to a nice
  userspace-triggerable OOPS.

- vmwgfx: This driver bothered with an implementation to return 0 as
  the handle (which is the canonical no-obj gem handle).

All have in common that ->create_handle doesn't really make too much
sense for them - that ioctl is used only for seamless fb takeover in
the radeon/nouveau/i915 ddx drivers. So allow drivers to not implement
this and return a consistent -ENODEV.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 0 insertions, 1 deletions

diff --git a/drivers/gpu/drm/udl/udl_fb.c b/drivers/gpu/drm/udl/udl_fb.c
index 829c4a76938c..f8904b4e68de 100644
--- a/drivers/gpu/drm/udl/udl_fb.c
+++ b/drivers/gpu/drm/udl/udl_fb.c
@@ -422,7 +422,6 @@ static void udl_user_framebuffer_destroy(struct drm_framebuffer *fb)
 static const struct drm_framebuffer_funcs udlfb_funcs = {
         .destroy = udl_user_framebuffer_destroy,
         .dirty = udl_user_framebuffer_dirty,
-        .create_handle = NULL,
 };