[Intel-gfx] [PATCH v9 6/6] drm/i915: expose rcs topology through query uAPI

[Chris Wilson]

Quoting Lionel Landwerlin (2018-01-18 15:22:27)
> On 18/01/18 15:18, Chris Wilson wrote:
> > Quoting Lionel Landwerlin (2018-01-18 14:45:31)
> >> +static int query_slice_info(struct drm_i915_private *dev_priv,
> >> +                           struct drm_i915_query_item *query_item)
> >> +{
> >> +       const struct sseu_dev_info *sseu = &INTEL_INFO(dev_priv)->sseu;
> >> +       struct drm_i915_query_slice_info slice_info;
> >> +
> >> +       if (query_item->flags != 0)
> >> +               return -EINVAL;
> >> +
> >> +       if (sseu->max_slices == 0)
> >> +               return -ENODEV;
> > So conclusion was to cancel all queries and not report a 0-length result
> > for unsupported? :)
> > -Chris
> >
> Looking at GETPARAM, some queries return ENODEV if not supported (look 
> at SLICE_MASK, so did the same here).
> Error are now reported in the s32 length field of the query item.
> Unless you've screwed up the pointer to the items, in which case you'll 
> get an error through the ioctl() return value.
> 
> Does that sounds sensible?

It does, my fault for overlooking you had made the change. And even
added it to the ioctl comments, making me look twice as bad ;)
-Chris