From mboxrd@z Thu Jan  1 00:00:00 1970
From: Daniel Vetter <daniel@ffwll.ch>
Subject: Re: [PATCH 2/2] drm/i915: Treat using a purged buffer
 as a source of EFAULT
Date: Tue, 4 Feb 2014 14:23:48 +0100
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To: Chris Wilson <chris@chris-wilson.co.uk>, Daniel Vetter <daniel@ffwll.ch>, intel-gfx@lists.freedesktop.org
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On Tue, Feb 04, 2014 at 11:36:39AM +0000, Chris Wilson wrote:
> On Tue, Feb 04, 2014 at 12:05:13PM +0100, Daniel Vetter wrote:
> > On Fri, Jan 31, 2014 at 11:34:58AM +0000, Chris Wilson wrote:
> > > Since a purged buffer is one without any associated pages, attempting to
> > > use it should generate EFAULT rather than EINVAL, as it is not strictly
> > > an invalid parameter.
> > > 
> > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> > 
> > Care to drop a quick testcase into i-g-t to encode this return value
> > change? Also, any plans to use this with userspace somehow, or what's the
> > motivation for this?
> 
> Just that we have other paths where inaccessible pages are reported back
> to userspace as EFAULT, and this is another case where we could distinguish
> the errno and so be more consistent.

Makes sense. I'll merge the patches once we have a bit of igt to enshrine
this.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch