In order to support simultaneous streaming from both capture devices,
start/stop vb2 calls need to be serialized to allow multiple concurrent
calls.

Signed-off-by: Helen Koike <helen.koike@collabora.com>

Series-to: linux-media@vger.kernel.org
Series-cc: linux-rockchip@lists.infradead.org
Series-cc: linux-kernel@vger.kernel.org
Series-cc: mchehab@kernel.org
Series-cc: hans.verkuil@cisco.com
Series-cc: tfiga@chromium.org
Series-cc: kernel@collabora.com

Series-version: 2
Series-changes: 2
- Rebased with media/master
- Removed the following patch from the series:
"media: staging: rkisp1: do not call s_stream if the entity is still in use"
It was replaced by "media: add v4l2_pipeline_stream_{enable,disable} helpers"
https://patchwork.linuxtv.org/cover/62233/

Cover-letter:
media: staging: rkisp1: allow simultaneous streaming from multiple capture devices
Hi,

This series adds support for simultaneous streaming from both capture
devices (rkisp1_selfpath and rkisp1_mainpath).

It depends on the following series for multistream to work properly, but
it doesn't mean it can't be merged before:

	"media: add v4l2_pipeline_stream_{enable,disable} helpers"
	https://patchwork.linuxtv.org/cover/62233/

And it is also available at:

	https://gitlab.collabora.com/koike/linux/tree/rockchip/isp/multistream

Patch 1/2 fixes return error handling from pm functions, which was
preventing the second stream to start.

Patch 2/2 serializes start/stop streaming calls, since they both
and modify shared variables.

This series was tested with:
============================

SEN_DEV=/dev/v4l-subdev3
ISP_DEV=/dev/v4l-subdev0
RSZ_SP_DEV=/dev/v4l-subdev2
RSZ_MP_DEV=/dev/v4l-subdev1
CAP_SP_DEV=/dev/video1
CAP_MP_DEV=/dev/video0

WIDTH=1920
HEIGHT=1080
RAW_CODE=SRGGB10_1X10
YUV_CODE=YUYV8_2X8

v4l2-ctl --set-subdev-fmt pad=0,width=$WIDTH,height=$HEIGHT,code=$RAW_CODE -d $SEN_DEV

v4l2-ctl --set-subdev-fmt pad=0,width=$WIDTH,height=$HEIGHT,code=$RAW_CODE -d $ISP_DEV
v4l2-ctl --set-subdev-selection pad=0,target=crop,top=0,left=0,width=$WIDTH,height=$HEIGHT -d $ISP_DEV

v4l2-ctl --set-subdev-selection pad=2,target=crop,top=0,left=0,width=$WIDTH,height=$HEIGHT -d $ISP_DEV
v4l2-ctl --set-subdev-fmt pad=2,width=$WIDTH,height=$HEIGHT,code=$YUV_CODE -d $ISP_DEV

v4l2-ctl --set-subdev-fmt pad=0,width=$WIDTH,height=$HEIGHT,code=$YUV_CODE -d $RSZ_SP_DEV
v4l2-ctl --set-subdev-fmt pad=1,width=$WIDTH,height=$HEIGHT,code=$YUV_CODE -d $RSZ_SP_DEV

v4l2-ctl --set-subdev-selection pad=0,target=crop,top=0,left=0,width=$WIDTH,height=$HEIGHT -d $RSZ_SP_DEV

v4l2-ctl --set-subdev-fmt pad=0,width=$WIDTH,height=$HEIGHT,code=$YUV_CODE -d $RSZ_MP_DEV
v4l2-ctl --set-subdev-fmt pad=1,width=$WIDTH,height=$HEIGHT,code=$YUV_CODE -d $RSZ_MP_DEV

v4l2-ctl --set-subdev-selection pad=0,target=crop,top=0,left=0,width=$WIDTH,height=$HEIGHT -d $RSZ_MP_DEV

v4l2-ctl -v width=$WIDTH,height=$HEIGHT,pixelformat=NV12 -d $CAP_SP_DEV
v4l2-ctl -v width=$WIDTH,height=$HEIGHT,pixelformat=NV12 -d $CAP_MP_DEV

sleep 1

v4l2-ctl --stream-mmap --stream-count=100 -d $CAP_SP_DEV --stream-to=/tmp/test_sp.raw &
v4l2-ctl --stream-mmap --stream-count=100 -d $CAP_MP_DEV --stream-to=/tmp/test_mp.raw &

wait
echo "Completed"

END