Commit ecff665f5e3f (drm/ttm: make ttm reservation calls...) causes system hang on Radeon RS780

[Maarten Lankhorst]

Op 10-07-13 11:22, Markus Trippelsdorf schreef:
> By simply copy/pasting a big document under LibreOffice my system hangs
> itself up. Only a hard reset gets it working again.
> see also: https://bugs.freedesktop.org/show_bug.cgi?id=66551
>
> I've bisected the issue to:
>
> commit ecff665f5e3f1c6909353e00b9420e45ae23d995
> Author: Maarten Lankhorst <m.b.lankhorst at gmail.com>
> Date:   Thu Jun 27 13:48:17 2013 +0200
>
>     drm/ttm: make ttm reservation calls behave like reservation calls
>     
>     This commit converts the source of the val_seq counter to
>     the ww_mutex api. The reservation objects are converted later,
>     because there is still a lockdep splat in nouveau that has to
>     resolved first.
>     
>     Signed-off-by: Maarten Lankhorst <maarten.lankhorst at canonical.com>
>     Reviewed-by: Jerome Glisse <jglisse at redhat.com>
>     Signed-off-by: Dave Airlie <airlied at redhat.com>
Hey,

Can you try current head with CONFIG_PROVE_LOCKING set and post the lockdep splat from dmesg, if any? If there is any locking issue lockdep should warn about it.
Lockdep will turn itself off after the first splat, so if the lockdep splat happens before running the affected parts those will have to be fixed first.

~Maarten