[PATCH v2 2/2] drm: automatic legacy gamma support

[Ville Syrjälä]

On Fri, Dec 11, 2020 at 01:24:49PM +0200, Tomi Valkeinen wrote:
> On 10/12/2020 20:06, kernel test robot wrote:
> > Hi Tomi,
> > 
> > I love your patch! Perhaps something to improve:
> > 
> > [auto build test WARNING on drm-intel/for-linux-next]
> > [also build test WARNING on linus/master v5.10-rc7]
> > [cannot apply to drm-tip/drm-tip anholt/for-next next-20201210]
> > [If your patch is applied to the wrong git tree, kindly drop us a note.
> > And when submitting patch, we suggest to use '--base' as documented in
> > https://git-scm.com/docs/git-format-patch]
> > 
> > url:    https://github.com/0day-ci/linux/commits/Tomi-Valkeinen/drm-fix-and-cleanup-legacy-gamma-support/20201208-215917
> > base:   git://anongit.freedesktop.org/drm-intel for-linux-next
> > config: i386-randconfig-m021-20201209 (attached as .config)
> > compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
> > 
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp at intel.com>
> > 
> > New smatch warnings:
> > drivers/gpu/drm/drm_color_mgmt.c:307 drm_crtc_legacy_gamma_set() error: potential null dereference 'blob'.  (drm_property_create_blob returns null)
> 
> I don't see how this could happen. There's no code path I see where drm_property_create_blob could
> return null...

IIRC we've received multiple similar nonsense reports from lkp, but
no explanation why it thinks it could ever be null. Hmm, maybe there
is a codepath somewhere that has a null check on the return value?

-- 
Ville Syrjälä
Intel