drm: optimize drm_framebuffer_remove
authorDaniel Vetter <daniel.vetter@ffwll.ch>
Tue, 11 Dec 2012 15:51:35 +0000 (16:51 +0100)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Sun, 20 Jan 2013 21:17:12 +0000 (22:17 +0100)
commitb62584e366ebcb3adffefad373a5abc4c4b677ca
tree12d9031be150949f3d4adcbe5aa7cd121df4e4c1
parent2fd5eabab02d9cdade04397eae0bfd49f452cdba
drm: optimize drm_framebuffer_remove

Now that all framebuffer usage is properly refcounted, we are no
longer required to hold the modeset locks while dropping the last
reference. Hence implemented a fastpath which avoids the potential
stalls associated with grabbing mode_config.lock for the case where
there's no other reference around.

Explain in a big comment why it is safe. Also update kerneldocs with
the new locking rules around drm_framebuffer_remove.

Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/drm_crtc.c