Re: [PATCH 5/5] drm/i915: non-interruptible sleeps can't handle -EGAIN

[Daniel Vetter <daniel@ffwll.ch>]

On Mon, Jun 25, 2012 at 09:23:38PM +0100, Chris Wilson wrote:
> On Sun, 24 Jun 2012 16:42:36 +0200, Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
> > So don't return -EAGAIN, even in the case of a gpu hang. Remap it to -EIO
> > instead.
> > 
> > This is a bit ugly because intel_ring_begin is all non-interruptible
> > and hence only returns -EIO. But as the comment in there says,
> > auditing all the callsites would be a pain.
> > 
> > To avoid duplicating code, reuse i915_gem_check_wedge in __wait_seqno.
> > Use the opportunity to clarify the different cases a bit with
> > comments.
> 
> Two separate patches. The first chunk sounds reasonable,
> non-interruptible is a little bit of misnomer here, we mostly use it to
> mean NOFAIL, and none of the callers are setup to handle EAGAIN. So
> reporting EIO seems reasonable.

This started as a patch to avoid returning -EAGAIN from intel_ring_begin
if mm.interruptible == false. After having added the same return -EIO
logic at a few places, I've noticed that I might as well shove it into
check_wedge and also call check_wedge from __wait_seqno (the older patch
check the retvalues at a few places instead).

Splitting this up would leave is in a state where we avoid returning
-EAGAIN at a few places within the functions called by intel_ring_begin,
but not all of them. Hence I think this should be all in one patch.
-Daniel
-- 
Daniel Vetter
Mail: daniel@ffwll.ch
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