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Message-ID: <f2dfd4b9-6573-fe08-1ba5-5c10c5980cb8@xs4all.nl>
Date: Thu, 18 Mar 2021 08:39:28 +0100
From: Hans Verkuil <hverkuil-cisco@...all.nl>
To: Ricardo Ribalda <ribalda@...omium.org>,
Laurent Pinchart <laurent.pinchart@...asonboard.com>,
Mauro Carvalho Chehab <mchehab@...nel.org>,
Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
tfiga@...omium.org
Cc: Hans Verkuil <hverkuil@...all.nl>
Subject: Re: [PATCH v6 16/17] media: uvcvideo: Return -EACCES to inactive
controls
Hi Ricardo,
On 17/03/2021 17:45, Ricardo Ribalda wrote:
> If a control is inactive return -EACCES to let the userspace know that
> the value will not be applied automatically when the control is active
> again.
>
> Signed-off-by: Ricardo Ribalda <ribalda@...omium.org>
> Suggested-by: Hans Verkuil <hverkuil@...all.nl>
In several of the patches in this series you added 'Suggested-by' or 'Credit-to'.
Please use <hverkuil-cisco@...all.nl> so Cisco gets the credit as well :-)
> ---
> drivers/media/usb/uvc/uvc_ctrl.c | 73 +++++++++++++++++++++++++-------
> drivers/media/usb/uvc/uvc_v4l2.c | 11 ++++-
> drivers/media/usb/uvc/uvcvideo.h | 3 +-
> 3 files changed, 69 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index af1d4d9b8afb..26d3494b401b 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -1046,10 +1046,62 @@ static int uvc_query_v4l2_class(struct uvc_video_chain *chain, u32 req_id,
> return 0;
> }
>
> -int uvc_ctrl_is_accesible(struct uvc_video_chain *chain, u32 v4l2_id, bool read)
> +static bool uvc_ctrl_is_inactive(struct uvc_video_chain *chain,
> + struct uvc_control *ctrl,
> + struct uvc_control_mapping *mapping)
> +{
> + struct uvc_control_mapping *master_map = NULL;
> + struct uvc_control *master_ctrl = NULL;
> + s32 val;
> + int ret;
> +
> + if (!mapping->master_id)
> + return false;
> +
> + __uvc_find_control(ctrl->entity, mapping->master_id, &master_map,
> + &master_ctrl, 0);
> +
> + if (!master_ctrl || !(master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR))
> + return false;
> +
> + ret = __uvc_ctrl_get(chain, master_ctrl, master_map, &val);
> + if (ret < 0 || val == mapping->master_manual)
> + return false;
> +
> + return true;
> +}
> +
> +int uvc_ctrl_is_accesible(struct uvc_video_chain *chain, u32 v4l2_id,
Same typo: accesible -> accessible
> + unsigned long ioctl)
> {
> struct uvc_control_mapping *mapping;
> struct uvc_control *ctrl;
> + bool read, try;
> +
> + switch (ioctl) {
> + case VIDIOC_G_EXT_CTRLS:
> + read = true;
> + try = false;
> + break;
> + case VIDIOC_S_EXT_CTRLS:
> + read = false;
> + try = false;
> + break;
> + case VIDIOC_TRY_EXT_CTRLS:
> + read = false;
> + try = true;
> + break;
> + case VIDIOC_G_CTRL:
> + read = true;
> + try = false;
> + break;
> + case VIDIOC_S_CTRL:
> + read = false;
> + try = false;
> + break;
> + default:
> + return -EINVAL;
> + }
That's ugly. Just remove the bools and switch and just check the ioctl below...
>
> if (__uvc_query_v4l2_class(chain, v4l2_id, 0) >= 0)
> return -EACCES;
> @@ -1064,6 +1116,9 @@ int uvc_ctrl_is_accesible(struct uvc_video_chain *chain, u32 v4l2_id, bool read)
> if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR) && !read)
> return -EACCES;
>
> + if (!read && !try && uvc_ctrl_is_inactive(chain, ctrl, mapping))
and this becomes:
if ((ioctl == VIDIOC_S_EXT_CTRLS || ioctl == VIDIOC_S_CTRL) &&
uvc_ctrl_is_inactive(chain, ctrl, mapping))
Much, much simpler!
> + return -EACCES;
> +
> return 0;
> }
>
> @@ -1086,8 +1141,6 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
> struct uvc_control_mapping *mapping,
> struct v4l2_queryctrl *v4l2_ctrl)
> {
> - struct uvc_control_mapping *master_map = NULL;
> - struct uvc_control *master_ctrl = NULL;
> const struct uvc_menu_info *menu;
> unsigned int i;
>
> @@ -1103,18 +1156,8 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
> if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR))
> v4l2_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
>
> - if (mapping->master_id)
> - __uvc_find_control(ctrl->entity, mapping->master_id,
> - &master_map, &master_ctrl, 0);
> - if (master_ctrl && (master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR)) {
> - s32 val;
> - int ret = __uvc_ctrl_get(chain, master_ctrl, master_map, &val);
> - if (ret < 0)
> - return ret;
> -
> - if (val != mapping->master_manual)
> - v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE;
> - }
> + if (uvc_ctrl_is_inactive(chain, ctrl, mapping))
> + v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE;
>
> if (!ctrl->cached) {
> int ret = uvc_ctrl_populate_cache(chain, ctrl);
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> index ce55b4bff687..8e9051a245c7 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -999,6 +999,10 @@ static int uvc_ioctl_g_ctrl(struct file *file, void *fh,
> struct v4l2_ext_control xctrl;
> int ret;
>
> + ret = uvc_ctrl_is_accesible(chain, ctrl->id, VIDIOC_G_CTRL);
> + if (ret)
> + return ret;
> +
> memset(&xctrl, 0, sizeof(xctrl));
> xctrl.id = ctrl->id;
>
> @@ -1023,6 +1027,10 @@ static int uvc_ioctl_s_ctrl(struct file *file, void *fh,
> struct v4l2_ext_control xctrl;
> int ret;
>
> + ret = uvc_ctrl_is_accesible(chain, ctrl->id, VIDIOC_S_CTRL);
> + if (ret)
> + return ret;
> +
> memset(&xctrl, 0, sizeof(xctrl));
> xctrl.id = ctrl->id;
> xctrl.value = ctrl->value;
> @@ -1054,8 +1062,7 @@ static int uvc_ctrl_check_access(struct uvc_video_chain *chain,
> int ret = 0;
>
> for (i = 0; i < ctrls->count; ++ctrl, ++i) {
> - ret = uvc_ctrl_is_accesible(chain, ctrl->id,
> - ioctl == VIDIOC_G_EXT_CTRLS);
> + ret = uvc_ctrl_is_accesible(chain, ctrl->id, ioctl);
> if (ret)
> break;
> }
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index 3288b118264e..4e86d0983d58 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -902,7 +902,8 @@ static inline int uvc_ctrl_rollback(struct uvc_fh *handle)
>
> int uvc_ctrl_get(struct uvc_video_chain *chain, struct v4l2_ext_control *xctrl);
> int uvc_ctrl_set(struct uvc_fh *handle, struct v4l2_ext_control *xctrl);
> -int uvc_ctrl_is_accesible(struct uvc_video_chain *chain, u32 v4l2_id, bool read);
> +int uvc_ctrl_is_accesible(struct uvc_video_chain *chain, u32 v4l2_id,
> + unsigned long ioctl);
>
> int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
> struct uvc_xu_control_query *xqry);
>
Regards,
Hans
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