[Intel-gfx] [PATCH 4/5] drm/i915: clear up wedged transitions

[Daniel Vetter]

On Tue, Nov 13, 2012 at 9:56 AM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> On Mon, 12 Nov 2012 23:07:52 +0100, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
>> While auditing the code I've noticed one place (the throttle ioctl)
>> which does not yet wait for the reset handler to complete and doesn't
>> properly decode the wedge state into -EAGAIN/-EIO. Fix this up by
>> calling the right helpers. This might explain the oddball "my
>> compositor just died in a successfull gpu reset" reports.
>
> It is a standalone bugfix and should be split into its own patch. But I
> don't think it quite has the impact you describe, since it only called
> by the ddx and only sna bothers to check the error code.  And one
> side-effect is that I think for especilly this case
> i915_gem_check_wedge() should be setting set_need_resched() before
> returning -EAGAIN.

Yeah, I've somehow ended up being lazy yesterday, will split out. For
the need-resched. Wrt the set_need_resched I think we're ok, to avoid
busy-looping I've added a call to i915_gem_wait_for_error. And imo
there's no need to micro-optimize the reset handling by getting of the
cpu a notch earlier. I'll extend the commit message of the split-out
patch to mention that little detail.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch