[Intel-gfx] [PATCH 4/5] drm/i915: check the power well on i915_pipe_enabled

[Daniel Vetter]

On Tue, May 7, 2013 at 4:18 PM, Paulo Zanoni <przanoni at gmail.com> wrote:
> 2013/5/7 Daniel Vetter <daniel at ffwll.ch>:
>> On Fri, May 03, 2013 at 12:15:39PM -0300, Paulo Zanoni wrote:
>>> From: Paulo Zanoni <paulo.r.zanoni at intel.com>
>>>
>>> This fixes "unclaimed register" messages when the power well is
>>> disabled and there's a GPU hang.
>>
>> How does this blow up in a gpu hang? Afaics pipe_enabled is mostly called
>> in the vblank code, so this should blow up any time we call a vblank
>> function on a disabled pipe ...
>
> If I add patches to also detect unclaimed "reads" instead of just
> writes and some dump_stack() calls, then call ZZ_hangman:

Yeah, reading the gpu reset code I've stumbled over the irq
install/unistall stuff. I still wondered why you've mentioned this and
not the vblank stuff itself. Does that nowhere show up when running
i-g-t? I've somewhat expected that kms_flip would hit it. If not I
need to add another wishlist subtest ;-)
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch