[Intel-gfx] [bug report] drm/i915/ttm: add tt shmem backend

[Dan Carpenter]

On Thu, Nov 18, 2021 at 03:15:31PM +0000, Matthew Auld wrote:
> On 18/11/2021 15:01, Dan Carpenter wrote:
> > Hello Matthew Auld,
> > 
> > The patch 7ae034590cea: "drm/i915/ttm: add tt shmem backend" from Oct
> > 18, 2021, leads to the following Smatch static checker warning:
> > 
> > 	drivers/gpu/drm/i915/gem/i915_gem_ttm.c:335 i915_ttm_eviction_valuable()
> > 	warn: signedness bug returning '(-16)'
> > 
> > drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> >      324 static bool i915_ttm_eviction_valuable(struct ttm_buffer_object *bo,
> >                 ^^^^
> > 
> >      325                                        const struct ttm_place *place)
> >      326 {
> >      327         struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
> >      328
> >      329         /*
> >      330          * EXTERNAL objects should never be swapped out by TTM, instead we need
> >      331          * to handle that ourselves. TTM will already skip such objects for us,
> >      332          * but we would like to avoid grabbing locks for no good reason.
> >      333          */
> >      334         if (bo->ttm && bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL)
> > --> 335                 return -EBUSY;
> >                          ^^^^^^^^^^^^^^
> > This should be return false probably.
> 
> Oh, indeed. Did you also want to send a patch for that? Thanks.
> 

Sure.  Will do.

regards,
dan carpenter