Re: [Intel-gfx] [PATCH] drm/i915/ttm: fix large buffer population trucation

[Matthew Auld <matthew.william.auld@gmail.com>]

On Mon, 13 Dec 2021 at 13:03, Matthew Auld <matthew.auld@intel.com> wrote:
>
> On 10/12/2021 19:50, Robert Beckett wrote:
> > ttm->num_pages is uint32_t which was causing very large buffers to
> > only populate a truncated size.
> >
> > This fixes gem_create@create-clear igt test on large memory systems.
> >
> > Fixes: 7ae034590cea ("drm/i915/ttm: add tt shmem backend")
> > Signed-off-by: Robert Beckett <bob.beckett@collabora.com>
>
> Nice catch,
> Reviewed-by: Matthew Auld <matthew.auld@intel.com>

Pushed to drm-intel-gt-next. Thanks again for the fix.

>
> > ---
> >   drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> > index 218a9b3037c7..923cc7ad8d70 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> > @@ -166,7 +166,7 @@ static int i915_ttm_tt_shmem_populate(struct ttm_device *bdev,
> >       struct intel_memory_region *mr = i915->mm.regions[INTEL_MEMORY_SYSTEM];
> >       struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
> >       const unsigned int max_segment = i915_sg_segment_size();
> > -     const size_t size = ttm->num_pages << PAGE_SHIFT;
> > +     const size_t size = (size_t)ttm->num_pages << PAGE_SHIFT;
> >       struct file *filp = i915_tt->filp;
> >       struct sgt_iter sgt_iter;
> >       struct sg_table *st;
> >