Re: [REVIEWv3 PATCH 22/35] DocBook media: update control section.

[Sakari Ailus <sakari.ailus@xxxxxx>]

Hi Hans,

On Mon, Feb 17, 2014 at 10:57:37AM +0100, Hans Verkuil wrote:
...
> @@ -501,6 +511,32 @@ for (queryctrl.id = V4L2_CID_PRIVATE_BASE;;
>      </example>
>  
>      <example>
> +      <title>Enumerating all user controls (alternative)</title>
> +	<programlisting>
> +memset(&amp;queryctrl, 0, sizeof(queryctrl));
> +
> +queryctrl.id = V4L2_CTRL_CLASS_USER | V4L2_CTRL_FLAG_NEXT_CTRL;
> +while (0 == ioctl(fd, &VIDIOC-QUERYCTRL;, &amp;queryctrl)) {
> +	if (V4L2_CTRL_ID2CLASS(queryctrl.id) != V4L2_CTRL_CLASS_USER)
> +		break;
> +	if (queryctrl.flags &amp; V4L2_CTRL_FLAG_DISABLED)
> +		continue;
> +
> +	printf("Control %s\n", queryctrl.name);
> +
> +	if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
> +		enumerate_menu();
> +
> +	queryctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
> +}
> +if (errno != EINVAL) {
> +	perror("VIDIOC_QUERYCTRL");
> +	exit(EXIT_FAILURE);
> +}

This is wrong; errno is guaranteed to be valid only if there's been an
error.

-- 
Kind regards,

Sakari Ailus
e-mail: sakari.ailus@xxxxxx	XMPP: sailus@xxxxxxxxxxxxxx
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