[PATCH 01/13] drm/mgag200: Remove unnecessary NULL check in bo_unref

[Daniel Vetter]

On Mon, Apr 7, 2014 at 5:19 PM, Ian Romanick <idr at freedesktop.org> wrote:
> On 04/05/2014 02:44 AM, Daniel Vetter wrote:
>> ttm_bo_unref unconditionally calls kref_put on it's argument, so the
>> thing can't be NULL without already causing Oopses.
>
> Doesn't this mean the NULL check is in the wrong place (rather than the
> NULL check should be removed)?

Afaics chasing callchains it's a bug to call this with NULL pointer
and no one really should be doing it. Like David Herrmann said it's
sometimes useful if unref/free functions automatically cope with NULL,
but ttm buffers don't seem to be of this kind. So consistency with
other ttm drivers seems better, same with all the gem_free_object
callbacks.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch