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

[Ian Romanick]

On 04/07/2014 12:56 PM, Daniel Vetter wrote:
> 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.

That's fair.  I'm convinced.  Patches 1, 3, and 5 are also

Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>

> -Daniel