drm/atomic: Handle -EDEADLK with out-fences correctly
authorMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Mon, 14 Aug 2017 10:07:21 +0000 (12:07 +0200)
committerMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Mon, 14 Aug 2017 13:47:57 +0000 (15:47 +0200)
commit7f5d6dac548b983702dd7aac1d463bd88dff50a8
treeaf273b0ed62e08a4f9ed76a377aa5acef24f77cc
parent491ab4700d1b64f5cf2f9055e01613a923df5fab
drm/atomic: Handle -EDEADLK with out-fences correctly

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@collabora.co.uk>
Cc: Brian Starkey <brian.starkey@arm.com> (v10)
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: David Airlie <airlied@linux.ie>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: <stable@vger.kernel.org> # v4.10+
Testcase: kms_atomic_transitions.plane-all-modeset-transition-fencing
(with CONFIG_DEBUG_WW_MUTEX_SLOWPATH=y)
Link: https://patchwork.freedesktop.org/patch/msgid/20170814100721.13340-1-maarten.lankhorst@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> #intel-gfx on irc
drivers/gpu/drm/drm_atomic.c