Hi Niklas,
On Fri, Oct 16, 2020 at 4:01 AM Niklas Söderlund
<niklas.soderlund+renesas@xxxxxxxxxxxx> 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
> internal state SUSPENDED is added to recode this.
>
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
Thanks for your patch!
> --- a/drivers/media/platform/rcar-vin/rcar-core.c
> +++ b/drivers/media/platform/rcar-vin/rcar-core.c
> +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
to be done?
> + * 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);
> +}
> +
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
