Re: [PATCH] videodev2: Set vb2_rect's width and height as unsigned

[Sakari Ailus <sakari.ailus@iki.fi>]

Hi Ricardo,

Thanks for the patch.

On Wed, Nov 06, 2013 at 01:49:25PM +0100, Ricardo Ribalda Delgado wrote:
...
> diff --git a/drivers/media/i2c/smiapp/smiapp-core.c b/drivers/media/i2c/smiapp/smiapp-core.c
> index ae66d91..9036e64 100644
> --- a/drivers/media/i2c/smiapp/smiapp-core.c
> +++ b/drivers/media/i2c/smiapp/smiapp-core.c
> @@ -2028,8 +2028,8 @@ static int smiapp_set_crop(struct v4l2_subdev *subdev,
>  	sel->r.width = min(sel->r.width, src_size->width);
>  	sel->r.height = min(sel->r.height, src_size->height);
>  
> -	sel->r.left = min(sel->r.left, src_size->width - sel->r.width);
> -	sel->r.top = min(sel->r.top, src_size->height - sel->r.height);
> +	sel->r.left = min(sel->r.left, (int) (src_size->width - sel->r.width));
> +	sel->r.top = min(sel->r.top, (int) (src_size->height - sel->r.height));

How about min_t(int, ... instead?

>  	*crops[sel->pad] = sel->r;
>  
> @@ -2121,8 +2121,10 @@ static int smiapp_set_selection(struct v4l2_subdev *subdev,
>  
>  	sel->r.left = max(0, sel->r.left & ~1);
>  	sel->r.top = max(0, sel->r.top & ~1);
> -	sel->r.width = max(0, SMIAPP_ALIGN_DIM(sel->r.width, sel->flags));
> -	sel->r.height = max(0, SMIAPP_ALIGN_DIM(sel->r.height, sel->flags));
> +	sel->r.width = max_t(unsigned int, 0,
> +			SMIAPP_ALIGN_DIM(sel->r.width, sel->flags));
> +	sel->r.height = max_t(unsigned int, 0,
> +			SMIAPP_ALIGN_DIM(sel->r.height, sel->flags));

The purpose of this check is to ensure the number is at least zero, and as
width and height are now unsigned, max_t() won't be needed anymore. Only
SMIAPP_ALIGN_DIM() is.

I can't see any harm from that, though --- there could be redundant checks
in other drivers, too.

>  	sel->r.width = max_t(unsigned int,
>  			     sensor->limits[SMIAPP_LIMIT_MIN_X_OUTPUT_SIZE],

Do you think it'd be worth adding a note on this change to the list of V4L2
in each kernel version in Documentation/DocBook/media/v4l/compat.xml?

-- 
Kind regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi	XMPP: sailus@retiisi.org.uk