[PATCH v3 12/12] media: staging: rkisp1: cap: protect access to buf with the spin lock

[Tomasz Figa]

Hi Dafna,

On Tue, Sep 22, 2020 at 01:34:02PM +0200, Dafna Hirschfeld wrote:
> The function 'rkisp1_stream_start' calls 'rkisp1_set_next_buf'
> which access the buffers, so the call should be protected by
> taking the cap->buf.lock.
> After this patch, all locks are reviewed and commented so remove
> the TODO item "review and comment every lock"
> 
> Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld at collabora.com>
> ---
>  drivers/staging/media/rkisp1/TODO             | 1 -
>  drivers/staging/media/rkisp1/rkisp1-capture.c | 2 ++
>  2 files changed, 2 insertions(+), 1 deletion(-)
> 

Thank you for the patch. Please see my comments inline.

> diff --git a/drivers/staging/media/rkisp1/TODO b/drivers/staging/media/rkisp1/TODO
> index f0c90d1c86a8..9662e9b51c7f 100644
> --- a/drivers/staging/media/rkisp1/TODO
> +++ b/drivers/staging/media/rkisp1/TODO
> @@ -1,6 +1,5 @@
>  * Fix pad format size for statistics and parameters entities.
>  * Fix checkpatch errors.
> -* Review and comment every lock
>  * Handle quantization
>  * streaming paths (mainpath and selfpath) check if the other path is streaming
>  in several places of the code, review this, specially that it doesn't seem it
> diff --git a/drivers/staging/media/rkisp1/rkisp1-capture.c b/drivers/staging/media/rkisp1/rkisp1-capture.c
> index 012c0825a386..b9e56dab77af 100644
> --- a/drivers/staging/media/rkisp1/rkisp1-capture.c
> +++ b/drivers/staging/media/rkisp1/rkisp1-capture.c
> @@ -913,6 +913,7 @@ static void rkisp1_stream_start(struct rkisp1_capture *cap)
>  	cap->ops->config(cap);
>  
>  	/* Setup a buffer for the next frame */
> +	spin_lock_irq(&cap->buf.lock);
>  	rkisp1_set_next_buf(cap);
>  	cap->ops->enable(cap);
>  	/* It's safe to config ACTIVE and SHADOW regs for the
> @@ -930,6 +931,7 @@ static void rkisp1_stream_start(struct rkisp1_capture *cap)
>  			     RKISP1_CIF_MI_INIT_SOFT_UPD, RKISP1_CIF_MI_INIT);
>  		rkisp1_set_next_buf(cap);
>  	}
> +	spin_unlock_irq(&cap->buf.lock);
>  	cap->is_streaming = true;

Should the is_streaming flag be protected in some way?

Also, similarly to the other nodes, is the flag actually needed?

Best regards,
Tomasz