Re: [PATCH] drm/xe: Fix stolen size check to allow equal WOPCM size

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Tue, Oct 21, 2025 at 12:09:44PM -0400, Lin, Shuicheng wrote:
> Thanks Matthew for the review.
> 
> Hi xe maintainers,
> Could you please help me review and merge it?
> Thanks in advance for your support.

Double sorry here, for the delay and for missing this case where
the stolen is solely the wocpm.

pushed to drm-xe-next now.

Thanks,
Rodrigo.

> 
> Best Regards
> Shuicheng
> 
> On Fri, Oct 17, 2025 1:55 AM Matthew Auld wrote:
> > On 16/10/2025 23:55, Shuicheng Lin wrote:
> > > On some platforms without dedicated stolen memory, the calculated
> > > stolen size may be exactly equal to the WOPCM size. The current
> > > assertion incorrectly requires it to be strictly greater, causing a
> > > false failure. Relax the check to allow equality.
> > >
> > > Fixes: 65369b8e2961 ("drm/xe: Change return type of detect_bar2_dgfx()
> > > from s64 to u64")
> > > Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/6359
> > > Cc: Matthew Auld <matthew.auld@intel.com>
> > > Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> > > Signed-off-by: Shuicheng Lin <shuicheng.lin@intel.com>
> > 
> > Looking at the logs for PVC it has previously never been probed with an actual
> > usable stolen area it seems, so this looks correct to me.
> > 
> > Reviewed-by: Matthew Auld <matthew.auld@intel.com>
> > 
> > > ---
> > >   drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c | 2 +-
> > >   1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
> > > b/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
> > > index e368b2a36bac..1bddecfb723a 100644
> > > --- a/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
> > > +++ b/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
> > > @@ -106,7 +106,7 @@ static u64 detect_bar2_dgfx(struct xe_device *xe,
> > > struct xe_ttm_stolen_mgr *mgr)
> > >
> > >   	stolen_size = tile_size - mgr->stolen_base;
> > >
> > > -	xe_assert(xe, stolen_size > wopcm_size);
> > > +	xe_assert(xe, stolen_size >= wopcm_size);
> > >   	stolen_size -= wopcm_size;
> > >
> > >   	/* Verify usage fits in the actual resource available */
>