[Intel-gfx] [PATCH] drm/vgem: Allow root to inject hanging fences onto dmabufs

[Chris Wilson]

On Wed, Jul 20, 2016 at 08:39:43PM +0100, Chris Wilson wrote:
> When performing driver testing, one factor we want to test is how we
> handle a foreign fence that is never signaled. We can wait on that fence
> indefinitely, in which case the driver appears hung, or we can take some
> remedial action (with risks regarding the state of any shared content).
> Whatever the action choosen by the driver, in order to perform the test
> we want to disable the safety feature of vgem fence (which is then used
> to test implicit dma-buf fencing). This is regarded as a highly
> dangerous feature and so hidden behind an expert config option and only
> available to root when enabled.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

Ping. This is invaluable for my testing (some tests are impossible
without it).

The only comment was by Kristian asking why this should be root-only
which nicely contrasts the earlier *demand* that this should be root-only
and removed from the default set of vgem capabilities.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre