Re: [PATCH 1/4] rcar-vin: Do not try to stop stream if not running

[Jacopo Mondi <jacopo@jmondi.org>]

Hi Niklas,

On Thu, Nov 12, 2020 at 11:51:44PM +0100, Niklas Söderlund wrote:
> Do not attempt to stop the streaming if the stream is not running.
>
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> ---
>  drivers/media/platform/rcar-vin/rcar-dma.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/drivers/media/platform/rcar-vin/rcar-dma.c b/drivers/media/platform/rcar-vin/rcar-dma.c
> index 5a5f0e5007478c8d..eae25972ed7df2b6 100644
> --- a/drivers/media/platform/rcar-vin/rcar-dma.c
> +++ b/drivers/media/platform/rcar-vin/rcar-dma.c
> @@ -1302,6 +1302,11 @@ void rvin_stop_streaming(struct rvin_dev *vin)
>
>  	spin_lock_irqsave(&vin->qlock, flags);
>
> +	if (vin->state == STOPPED) {
> +		spin_unlock_irqrestore(&vin->qlock, flags);
> +		return;

Do I read it right that, in case a double stop is attempted, returning
here is not enough as the caller:

{
	rvin_stop_streaming(vin);

	/* Free scratch buffer. */
	dma_free_coherent(vin->dev, vin->format.sizeimage, vin->scratch,
			  vin->scratch_phys);

	return_unused_buffers(vin, VB2_BUF_STATE_ERROR);
}

Are the potential double call to dma_free_coherent and the buffer
return procedure harmless ?

Thanks
   j

> +	}
> +
>  	vin->state = STOPPING;
>
>  	/* Wait until only scratch buffer is used, max 3 interrupts. */
> --
> 2.29.2
>