drm-next-misc merge breaks vmwgfx

[Thomas Hellstrom]

On 04/06/2017 05:01 PM, Daniel Vetter wrote:
> On Thu, Apr 6, 2017 at 4:56 PM, Thomas Hellstrom <thellstrom at vmware.com> wrote:
>> On 04/06/2017 04:47 PM, Daniel Vetter wrote:
>>> On Thu, Apr 6, 2017 at 4:10 PM, Thomas Hellstrom <thellstrom at vmware.com> wrote:
>>>> Also, when testing the tip of drm-misc-next (with the non-atomic vmwgfx)
>>>> there appeared to be warnings about a non-NULL
>>>> dev->mode_config.acquire_ctx. I'll see if I can reproduce those, but
>>>> perhaps removing the line
>>>>
>>>> dev->mode_config.acquire_ctx = &ctx
>>>>
>>>> in drm_mode_setcrtc()
>>>>
>>>> is part of the problem.
>>> Hm, where do you hit that? And by tip of drm-misc-next, do you mean
>>> the very latest state, which includes atomic vmwgfx, or is this with
>>> the non-atomic vmwgfx? Please paste the backtraces (and for which tree
>>> they are).
>>> -Daniel
>> Actually this must have been from a confused rebase-bisect state
>> somewhere. I can't reproduce this.
> Have you changed CONFIG_DEBUG_WW_MUTEX_SLOWPATH perhaps? Without this
> you shouldn't be able to hit any retry path (so minus warnings the
> patch you bisected won't have an affected), with you will hit the
> deadlock retry paths pseudo-randomly. It might take a few trials to
> hit it again, depending upon timing.
> -Daniel

No, it's not that. I've set it to off for all these tests, but lockdep
and hang-checks on.

/Thomas