[Intel-gfx] [CI, v3, 1/2] drm/i915: Prevent a race during I915_GEM_MMAP ioctl with WC set

[Chris Wilson]

Quoting Guenter Roeck (2019-02-28 22:27:35)
> On Thu, Feb 28, 2019 at 10:18:32PM +0000, Chris Wilson wrote:
> > 
> > If you have userspace that is broken, we need to fix it. We can get away
> > with quietly changing ABI only so long as nobody notices. It sounds like
> > you have some userspace that will break if you updated the kernel; ergo
> > we have a problem.
> > 
> > We just need that as a clear statement so that we have the user impact
> > recorded.
> 
> Yes, it does break our userspace code. I fixed the problem in our kernels
> with the following patch:
> 
And what userspace is that? Details for the log, please.
-Chris