Re: [PATCH v2 04/14] media: staging: rkisp1: params: don't release lock in isr before buffer is done

[Helen Koike <helen.koike@collabora.com>]

On 8/15/20 7:37 AM, Dafna Hirschfeld wrote:
> In the irq handler 'rkisp1_params_isr', the lock 'config_lock'
> should be held as long as the current buffer is used. Otherwise the
> stop_streaming calback might remove it from the list and
> pass it to userspace while it is referenced in the irq handler.
> 
> Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>

Acked-by: Helen Koike <helen.koike@collabora.com>

Thanks
Helen

> ---
>  drivers/staging/media/rkisp1/rkisp1-params.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/staging/media/rkisp1/rkisp1-params.c b/drivers/staging/media/rkisp1/rkisp1-params.c
> index eb77b4ed8655..0c2bb2eefb22 100644
> --- a/drivers/staging/media/rkisp1/rkisp1-params.c
> +++ b/drivers/staging/media/rkisp1/rkisp1-params.c
> @@ -1210,10 +1210,11 @@ void rkisp1_params_isr(struct rkisp1_device *rkisp1)
>  	if (!list_empty(&params->params))
>  		cur_buf = list_first_entry(&params->params,
>  					   struct rkisp1_buffer, queue);
> -	spin_unlock(&params->config_lock);
>  
> -	if (!cur_buf)
> +	if (!cur_buf) {
> +		spin_unlock(&params->config_lock);
>  		return;
> +	}
>  
>  	new_params = (struct rkisp1_params_cfg *)(cur_buf->vaddr[0]);
>  
> @@ -1223,12 +1224,11 @@ void rkisp1_params_isr(struct rkisp1_device *rkisp1)
>  	/* update shadow register immediately */
>  	rkisp1_param_set_bits(params, RKISP1_CIF_ISP_CTRL, RKISP1_CIF_ISP_CTRL_ISP_CFG_UPD);
>  
> -	spin_lock(&params->config_lock);
>  	list_del(&cur_buf->queue);
> -	spin_unlock(&params->config_lock);
>  
>  	cur_buf->vb.sequence = frame_sequence;
>  	vb2_buffer_done(&cur_buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
> +	spin_unlock(&params->config_lock);
>  }
>  
>  static const struct rkisp1_cif_isp_awb_meas_config rkisp1_awb_params_default_config = {
>