[PATCH] drm/atomic: Handle -EDEADLK with out-fences correctly

[Daniel Vetter]

On Fri, Aug 18, 2017 at 10:13:08PM +0200, Daniel Vetter wrote:
> On Fri, Aug 18, 2017 at 01:59:10PM -0300, Gustavo Padovan wrote:
> > 2017-08-14 Maarten Lankhorst <maarten.lankhorst at linux.intel.com>:
> > 
> > > complete_crtc_signaling is freeing fence_state, but when retrying
> > > num_fences and fence_state are not zero'd. This caused duplicate
> > > fd's in the fence_state array, followed by a BUG_ON in fs/file.c
> > > because we reallocate freed memory, and installing over an existing
> > > fd, or potential other fun.
> > > 
> > > Zero fence_state and num_fences correctly in the retry loop, which
> > > allows kms_atomic_transition to pass.
> > > 
> > > Fixes: beaf5af48034 ("drm/fence: add out-fences support")
> > > Cc: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
> > > Cc: Brian Starkey <brian.starkey at arm.com> (v10)
> > > Cc: Sean Paul <seanpaul at chromium.org>
> > > Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> > > Cc: Jani Nikula <jani.nikula at linux.intel.com>
> > > Cc: David Airlie <airlied at linux.ie>
> > > Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> > > Cc: <stable at vger.kernel.org> # v4.10+
> > > Testcase: kms_atomic_transitions.plane-all-modeset-transition-fencing
> > > (with CONFIG_DEBUG_WW_MUTEX_SLOWPATH=y)
> > > ---
> > >  drivers/gpu/drm/drm_atomic.c | 6 ++++--
> > >  1 file changed, 4 insertions(+), 2 deletions(-)
> > 
> > Reviewed-by: Gustavo Padovan <gustavo.padovan at collabora.com>
> 
> Hm somehow this fell through, applied to drm-misc-fixes.

Actually it was merged already, I was on an old -fixes.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch