From a952e0103f86d818a444923adeef50fdcb3f70b9 Mon Sep 17 00:00:00 2001
From: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Date: Tue, 13 Dec 2016 17:46:31 +0000
Subject: [PATCHv3 0/4] v4l: vsp1: Fix suspend/resume and race on M2M pipelines

This small patchset helps rework the VSP1 driver to repair an issue on
suspend/resume operations whereby the pipeline does not get reconfigured after
it has been re-initialised following a resume operation.

Along side this, there was an intrinsic race in the vsp1_video_start_streaming()
function whereby multiple streams operating through a BRU, could find themselves
commencing an operation before the pipeline has been configured, or worse -
commencing, just as the pipeline is being configured resulting in a null pointer
dereference on pipe->dl.

This series superceeds a previous effort to fix the BRU race.

Patch [1/4] is a code move only, with no functional change.
Patch [2/4] refactors the vsp1_video_start_streaming() function and fixes both
            suspend/resume, and the BRU race in a single change
Patch [3/4] removes the context scoped 'pipe->dl' which has been susceptible to
            races and isn't required to be in the context.
Patch [4/4] is an RFC patch really, that fixes a segfault on error paths  and I
            certainly expect feedback and brief discussion. Please drop Patch 4
            in the event of any further discussion, and don't consider it as
            blocking for the first three patches of this series.

v3:
 - Move configured=false from vsp1_device_init to vsp1_reset_wpf()
 - Clean up flag dereferencing with a local struct *

v2:
 - Refactor video pipeline configuration implementation to solve both suspend
   resume and the VSP BRU race in a single change

v1:
 - Original pipeline configuration rework

Kieran Bingham (4):
  v4l: vsp1: Move vsp1_video_setup_pipeline()
  v4l: vsp1: Refactor video pipeline configuration
  v4l: vsp1: Use local display lists and remove global pipe->dl
  media: Catch null pipes on pipeline stop

 drivers/media/media-entity.c             |   2 +
 drivers/media/platform/vsp1/vsp1_drm.c   |  20 ++---
 drivers/media/platform/vsp1/vsp1_drv.c   |   4 +
 drivers/media/platform/vsp1/vsp1_pipe.c  |   1 +
 drivers/media/platform/vsp1/vsp1_pipe.h  |   4 +-
 drivers/media/platform/vsp1/vsp1_video.c | 127 +++++++++++++++----------------
 6 files changed, 79 insertions(+), 79 deletions(-)

--
2.7.4
media: Catch null pipes on pipeline stop

media_entity_pipeline_stop() can be called through error paths with a
NULL entity pipe object. In this instance, stopping is a no-op, so
simply return without any action

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
1 file changed