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From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Ricardo Ribalda <ribalda@chromium.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>,
	Tomasz Figa <tfiga@chromium.org>,
	linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
	senozhatsky@chromium.org, Hans Verkuil <hverkuil@xs4all.nl>,
	Hans Verkuil <hverkuil-cisco@xs4all.nl>
Subject: Re: [PATCH v3 4/8] media: uvcvideo: set error_idx to count on EACCESS
Date: Sat, 13 Mar 2021 00:42:04 +0200	[thread overview]
Message-ID: <YEvuPOnu3Rjm2Bbk@pendragon.ideasonboard.com> (raw)
In-Reply-To: <20210312124830.1344255-5-ribalda@chromium.org>

Hi Ricardo,

Thank you for the patch.

On Fri, Mar 12, 2021 at 01:48:26PM +0100, Ricardo Ribalda wrote:
> If an error is found when validating the list of controls passed with
> VIDIOC_G_EXT_CTRLS, then error_idx shall be set to ctrls->count to
> indicate
> to userspace that no actual hardware was touched.
> 
> It would have been much nicer of course if error_idx could point to the
> control index that failed the validation, but sadly that's not how the
> API was designed.
> 
> Fixes v4l2-compliance:
> Control ioctls (Input 0):
>                 fail: v4l2-test-controls.cpp(645): invalid error index write only control
>         test VIDIOC_G/S/TRY_EXT_CTRLS: FAIL
> 
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Still pending discussions in v2.

> ---
>  drivers/media/usb/uvc/uvc_v4l2.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> index 157310c0ca87..36eb48622d48 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -1073,7 +1073,8 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
>  		ret = uvc_ctrl_get(chain, ctrl);
>  		if (ret < 0) {
>  			uvc_ctrl_rollback(handle);
> -			ctrls->error_idx = i;
> +			ctrls->error_idx = (ret == -EACCES) ?
> +						ctrls->count : i;
>  			return ret;
>  		}
>  	}

-- 
Regards,

Laurent Pinchart

  reply	other threads:[~2021-03-12 22:43 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-12 12:48 [PATCH v3 0/8] Fix v4l2-compliance errors Ricardo Ribalda
2021-03-12 12:48 ` [PATCH v3 1/8] media: v4l2-ioctl: Fix check_ext_ctrls Ricardo Ribalda
2021-03-12 12:48 ` [PATCH v3 2/8] media: uvcvideo: Set capability in s_param Ricardo Ribalda
2021-03-12 12:48 ` [PATCH v3 3/8] media: uvcvideo: Return -EIO for control errors Ricardo Ribalda
2021-03-12 12:48 ` [PATCH v3 4/8] media: uvcvideo: set error_idx to count on EACCESS Ricardo Ribalda
2021-03-12 22:42   ` Laurent Pinchart [this message]
2021-03-12 12:48 ` [PATCH v3 5/8] media: uvcvideo: refactor __uvc_ctrl_add_mapping Ricardo Ribalda
2021-03-12 22:40   ` Laurent Pinchart
2021-03-12 12:48 ` [PATCH v3 6/8] media: uvcvideo: Add support for V4L2_CTRL_TYPE_CTRL_CLASS Ricardo Ribalda
2021-03-12 22:44   ` Laurent Pinchart
2021-03-12 12:48 ` [PATCH v3 7/8] media: uvcvideo: Set a different name for the metadata entity Ricardo Ribalda
2021-03-12 22:27   ` Laurent Pinchart
2021-03-12 23:17     ` Ricardo Ribalda Delgado
2021-03-12 23:28       ` Laurent Pinchart
2021-03-12 23:47         ` Ricardo Ribalda Delgado
2021-03-12 12:48 ` [PATCH v3 8/8] uvc: use vb2 ioctl and fop helpers Ricardo Ribalda
2021-03-12 13:59   ` Hans Verkuil

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