[Intel-gfx] [RFC PATCH 1/1] drm/i915: Never allow userptr into the new mapping types

[Janusz Krzysztofik]

On Friday, January 31, 2020 3:32:21 PM CET Chris Wilson wrote:
> Quoting Janusz Krzysztofik (2020-01-31 13:20:37)
> > Commit 4f2a572eda67 ("drm/i915/userptr: Never allow userptr into the
> > mappable GGTT") made I915_GEM_MMAP_GTT IOCTLs to fail when atepmted
> > on a userptr object in order to protect from a lockdep splat.  Later
> > on, new mapping types were introduced by commit cc662126b413
> > ("drm/i915: Introduce DRM_I915_GEM_MMAP_OFFSET").  Those new mapping
> > types suffer from the same lockdep splat issue but they now succeed
> > when tried on top of a userptr object.  Fix it.
> > 
> > While being at it, return -EINVAL which seems to better reflect the
> > reason for the failure than -ENODEV.
> 
> No. It is not a user error, it's a failure to implement support for it,
> so we parcel it off as an incompatible device.

How about -ENOTSUP?

Thanks,
Janusz

> -Chris
>