drm: Declare that create drm_mm nodes with size 0 is illegal
authorChris Wilson <chris@chris-wilson.co.uk>
Wed, 3 Aug 2016 18:26:28 +0000 (19:26 +0100)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Mon, 8 Aug 2016 08:05:21 +0000 (10:05 +0200)
commitaafdcfd3f9aa3c9f77ae4e9385f21bf9ae120d3e
tree9014ad1eabd35eb5f85730e321c41b0c7cb1881e
parenta3ccc461668951c14b7c656233b993f0dea326ce
drm: Declare that create drm_mm nodes with size 0 is illegal

At a higher level, all objects are created with definite size i.e. 0 is
illegal. In forthcoming patches, this assumption is dependent upon in
the drm_mm range manager, i.e. trying to create a drm_mm node with size
0 will have undefined behaviour. Add a couple of WARNs upon creating the
drm_mm node to prevent later bugs.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1470248788-30873-1-git-send-email-chris@chris-wilson.co.uk
drivers/gpu/drm/drm_mm.c