Hi Niklas,
On Fri, Oct 16, 2020 at 01:14:08AM +0200, Niklas Söderlund wrote:
> Add support for suspend and resume by stopping and starting the video
> pipeline while still retaining all buffers given to the driver by
> user-space and internally allocated ones, this gives the application a
> seamless experience.
>
> Buffers are never returned to user-space unprocessed so user-space don't
> notice when suspending. When resuming the driver restarts the capture
> session using the internal scratch buffer, this happens before
> user-space is unfrozen, this leads to speedy response times once the
> application resumes its execution.
>
> As the entire pipeline is stopped on suspend all subdevices in use are
> also stopped, and if they enter a shutdown state when not streaming
> (such as the R-Car CSI-2 driver) they too will be suspended and resumed
> in sync with the VIN driver.
>
> To be able to do keep track of which VINs should be resumed a new
s/to do/to/
> internal state SUSPENDED is added to recode this.
>
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
> ---
> drivers/media/platform/rcar-vin/rcar-core.c | 51 +++++++++++++++++++++
> drivers/media/platform/rcar-vin/rcar-vin.h | 10 ++--
> 2 files changed, 57 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/platform/rcar-vin/rcar-core.c b/drivers/media/platform/rcar-vin/rcar-core.c
> index 34d003e0e9b9c25a..4adf4ce518f79c93 100644
> --- a/drivers/media/platform/rcar-vin/rcar-core.c
> +++ b/drivers/media/platform/rcar-vin/rcar-core.c
> @@ -918,6 +918,54 @@ static int rvin_mc_init(struct rvin_dev *vin)
> return ret;
> }
>
> +/* -----------------------------------------------------------------------------
> + * Suspend / Resume
> + */
> +
> +static int __maybe_unused rvin_suspend(struct device *dev)
> +{
> + struct rvin_dev *vin = dev_get_drvdata(dev);
> +
> + if (vin->state != RUNNING)
> + return 0;
> +
> + rvin_stop_streaming(vin);
This delay suspend untill all the userspace queued buffers are not
completed, right ?
> +
> + vin->state = SUSPENDED;
> +
> + return 0;
> +}
> +
> +static int __maybe_unused rvin_resume(struct device *dev)
> +{
> + struct rvin_dev *vin = dev_get_drvdata(dev);
> +
> + if (vin->state != SUSPENDED)
> + return 0;
> +
> + /*
> + * Restore group master CHSEL setting.
> + *
> + * This needs to be by every VIN resuming not only the master
> + * as we don't know if and in which order the master VINs will
> + * be resumed.
> + */
> + if (vin->info->use_mc) {
> + unsigned int master_id = rvin_group_id_to_master(vin->id);
> + struct rvin_dev *master = vin->group->vin[master_id];
> + int ret;
> +
> + if (WARN_ON(!master))
> + return -ENODEV;
> +
> + ret = rvin_set_channel_routing(master, master->chsel);
> + if (ret)
> + return ret;
> + }
> +
> + return rvin_start_streaming(vin);
> +}
> +
> /* -----------------------------------------------------------------------------
> * Platform Device Driver
> */
> @@ -1421,9 +1469,12 @@ static int rcar_vin_remove(struct platform_device *pdev)
> return 0;
> }
>
> +static SIMPLE_DEV_PM_OPS(rvin_pm_ops, rvin_suspend, rvin_resume);
> +
> static struct platform_driver rcar_vin_driver = {
> .driver = {
> .name = "rcar-vin",
> + .pm = &rvin_pm_ops,
> .of_match_table = rvin_of_id_table,
> },
> .probe = rcar_vin_probe,
> diff --git a/drivers/media/platform/rcar-vin/rcar-vin.h b/drivers/media/platform/rcar-vin/rcar-vin.h
> index 4ec8584709c847a9..4539bd53d9d41e9c 100644
> --- a/drivers/media/platform/rcar-vin/rcar-vin.h
> +++ b/drivers/media/platform/rcar-vin/rcar-vin.h
> @@ -49,16 +49,18 @@ enum rvin_csi_id {
> };
>
> /**
> - * STOPPED - No operation in progress
> - * STARTING - Capture starting up
> - * RUNNING - Operation in progress have buffers
> - * STOPPING - Stopping operation
> + * STOPPED - No operation in progress
> + * STARTING - Capture starting up
> + * RUNNING - Operation in progress have buffers
> + * STOPPING - Stopping operation
> + * SUSPENDED - Capture is suspended
> */
> enum rvin_dma_state {
> STOPPED = 0,
> STARTING,
> RUNNING,
> STOPPING,
> + SUSPENDED,
> };
>
> /**
> --
> 2.28.0
>
