Hi Helen, On 2020-04-03 18:33:09 -0300, Helen Koike wrote: > Hi, > > Media drivers need to iterate through the pipeline and call .s_stream() > callbacks in the subdevices. > > Instead of repeating code, add helpers for this. > > These helpers will go walk through the pipeline only visiting entities > that participates in the stream, i.e. it follows links from sink to source > (and not the opposite). > > Which means that in a topology like this https://bit.ly/3b2MxjI > calling v4l2_pipeline_stream_enable() from rkisp1_mainpath won't call > .s_stream(true) for rkisp1_resizer_selfpath. > > stream_count variable was added in v4l2_subdevice to handle nested calls > to the helpers. > This is useful when the driver allows streaming from more then one > capture device sharing subdevices. > > This patch came from the error I was facing when multistreaming from > rkisp1 driver, where stoping one capture would call s_stream(false) in > the pipeline, causing a stall in the second capture device. > > Also, the vimc patch https://patchwork.kernel.org/patch/10948833/ won't > be required with this patchset. > > This patchset was tested on rkisp1 and vimc drivers. I'm just curious, with this series applied can I stream simultaneously on multiple video devises using vimc? > > Other cleanup might be possible (but I won't add in this patchset as I > don't have the hw to test): > https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/qcom/camss/camss-video.c#n430 > https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/omap3isp/isp.c#n697 > https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/stm32/stm32-dcmi.c#n680 > https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/xilinx/xilinx-dma.c#n97 > > Changes in V2: > ==================== > The first version was calling the s_stream() callbacks from sensor to > capture. > > This was generating errors in the Scarlet Chromebook, when the sensor > was being enabled before the ISP. > > It make sense to enable subdevices from capture to sensor instead (which > is what most drivers do already). > > This v2 drops the changes from mc-entity.c, and re-implement helpers in > v4l2-common.c > > Overview of patches: > ==================== > > Path 1/3 adds the helpers in v4l2-common.c, allowing nested calls by > adding stream_count in the subdevice struct. > > Patch 2/3 cleanup rkisp1 driver to use the helpers. > > Patch 3/3 cleanup vimc driver to use the helpers. > > Helen Koike (3): > media: v4l2-common: add helper functions to call s_stream() callbacks > media: staging: rkisp1: use v4l2_pipeline_stream_{enable,disable} > helpers > media: vimc: use v4l2_pipeline_stream_{enable,disable} helpers > > drivers/media/platform/vimc/vimc-capture.c | 28 +++-- > drivers/media/platform/vimc/vimc-streamer.c | 49 +------- > drivers/media/v4l2-core/v4l2-common.c | 117 ++++++++++++++++++ > drivers/staging/media/rkisp1/rkisp1-capture.c | 76 +----------- > include/media/v4l2-common.h | 28 +++++ > include/media/v4l2-subdev.h | 2 + > 6 files changed, 173 insertions(+), 127 deletions(-) > > -- > 2.26.0 > -- Regards, Niklas Söderlund
