Re: [PATCH v2 4/4] media i.MX27 camera: handle overflows properly.

[Guennadi Liakhovetski <g.liakhovetski@xxxxxx>]

(removed baruch@xxxxxxxxxx - it bounces)

On Thu, 26 Jan 2012, Javier Martin wrote:

> 
> Signed-off-by: Javier Martin <javier.martin@xxxxxxxxxxxxxxxxx>
> ---
>  Changes since v1:
>  - Make ifs in irq callback mutually exclusive.
>  - Add new argument to mx27_camera_frame_done_emma() to handle errors.
> 
> ---
>  drivers/media/video/mx2_camera.c |   38 ++++++++++++++++----------------------
>  1 files changed, 16 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/media/video/mx2_camera.c b/drivers/media/video/mx2_camera.c
> index 71054ab..1759673 100644
> --- a/drivers/media/video/mx2_camera.c
> +++ b/drivers/media/video/mx2_camera.c
> @@ -1213,7 +1213,7 @@ static struct soc_camera_host_ops mx2_soc_camera_host_ops = {
>  };
>  
>  static void mx27_camera_frame_done_emma(struct mx2_camera_dev *pcdev,
> -		int bufnum)
> +		int bufnum, bool err)
>  {
>  	struct mx2_buffer *buf;
>  	struct vb2_buffer *vb;
> @@ -1262,7 +1262,10 @@ static void mx27_camera_frame_done_emma(struct mx2_camera_dev *pcdev,
>  		list_del_init(&buf->queue);
>  		do_gettimeofday(&vb->v4l2_buf.timestamp);
>  		vb->v4l2_buf.sequence = pcdev->frame_count;
> -		vb2_buffer_done(vb, VB2_BUF_STATE_DONE);
> +		if (err)
> +			vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
> +		else
> +			vb2_buffer_done(vb, VB2_BUF_STATE_DONE);
>  	}
>  
>  	pcdev->frame_count++;
> @@ -1297,21 +1300,12 @@ static irqreturn_t mx27_camera_emma_irq(int irq_emma, void *data)
>  	struct mx2_buffer *buf;
>  
>  	if (status & (1 << 7)) { /* overflow */
> -		u32 cntl;
> -		/*
> -		 * We only disable channel 1 here since this is the only
> -		 * enabled channel
> -		 *
> -		 * FIXME: the correct DMA overflow handling should be resetting
> -		 * the buffer, returning an error frame, and continuing with
> -		 * the next one.
> -		 */
> -		cntl = readl(pcdev->base_emma + PRP_CNTL);
> -		writel(cntl & ~(PRP_CNTL_CH1EN | PRP_CNTL_CH2EN),
> -		       pcdev->base_emma + PRP_CNTL);
> -		writel(cntl, pcdev->base_emma + PRP_CNTL);
> -	}
> -	if ((((status & (3 << 5)) == (3 << 5)) ||
> +		buf = list_entry(pcdev->active_bufs.next,
> +			struct mx2_buffer, queue);
> +		mx27_camera_frame_done_emma(pcdev,
> +					buf->bufnum, 1);

use "true" for bool variables.

> +		status &= ~(1 << 7);
> +	} else if ((((status & (3 << 5)) == (3 << 5)) ||
>  		((status & (3 << 3)) == (3 << 3)))
>  			&& !list_empty(&pcdev->active_bufs)) {
>  		/*
> @@ -1320,13 +1314,13 @@ static irqreturn_t mx27_camera_emma_irq(int irq_emma, void *data)
>  		 */
>  		buf = list_entry(pcdev->active_bufs.next,
>  			struct mx2_buffer, queue);
> -		mx27_camera_frame_done_emma(pcdev, buf->bufnum);
> +		mx27_camera_frame_done_emma(pcdev, buf->bufnum, 0);

"false"

>  		status &= ~(1 << (6 - buf->bufnum)); /* mark processed */
> +	} else if ((status & (1 << 6)) || (status & (1 << 4))) {
> +		mx27_camera_frame_done_emma(pcdev, 0, 0);

"false"

> +	} else if ((status & (1 << 5)) || (status & (1 << 3))) {
> +		mx27_camera_frame_done_emma(pcdev, 1, 0);

"false"

>  	}
> -	if ((status & (1 << 6)) || (status & (1 << 4)))
> -		mx27_camera_frame_done_emma(pcdev, 0);
> -	if ((status & (1 << 5)) || (status & (1 << 3)))
> -		mx27_camera_frame_done_emma(pcdev, 1);
>  
>  	writel(status, pcdev->base_emma + PRP_INTRSTATUS);
>  
> -- 
> 1.7.0.4
> 

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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