Re: [PATCH v7 6/7] media: uvcvideo: support V4L2_CTRL_WHICH_MIN/MAX_VAL

Yunke Cao
2022-09-20T07:53:54Z

Hi Laurent,

Thanks for the review.

On Thu, Aug 25, 2022 at 5:04 AM Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
>
> Hi Yunke,
>
> Thank you for the patch.
>
> On Tue, Jun 28, 2022 at 04:57:04PM +0900, Yunke Cao wrote:
> > Add support for V4L2_CTRL_WHICH_MIN/MAX_VAL in uvc driver.
> > It is useful for the V4L2_CID_UVC_REGION_OF_INTEREST_RECT control.
> >
> > Signed-off-by: Yunke Cao <yunkec@google.com>
> > ---
> > 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, 70 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> > index 00482269233a..b569d6824ac1 100644
> > --- a/drivers/media/usb/uvc/uvc_ctrl.c
> > +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> > @@ -1923,7 +1923,7 @@ int uvc_ctrl_get(struct uvc_video_chain *chain,
> > }
> >
> > int __uvc_ctrl_get_fixed_std(struct uvc_video_chain *chain,
> > - struct v4l2_ext_control *xctrl)
> > + struct v4l2_ext_control *xctrl, u32 v4l2_which)
> > {
> > struct v4l2_queryctrl qc = { .id = xctrl->id };
> > int ret = uvc_query_v4l2_ctrl(chain, &qc);
> > @@ -1931,16 +1931,69 @@ int __uvc_ctrl_get_fixed_std(struct uvc_video_chain *chain,
> > if (ret < 0)
> > return ret;
> >
> > - xctrl->value = qc.default_value;
> > + switch (v4l2_which) {
> > + case V4L2_CTRL_WHICH_DEF_VAL:
> > + xctrl->value = qc.default_value;
> > + break;
> > + case V4L2_CTRL_WHICH_MIN_VAL:
> > + xctrl->value = qc.minimum;
> > + break;
> > + case V4L2_CTRL_WHICH_MAX_VAL:
> > + xctrl->value = qc.maximum;
> > + break;
> > + default:
> > + return -EINVAL;
> > + }
> > +
> > return 0;
> > }
> >
> > +static int __uvc_ctrl_get_fixed_compound(struct uvc_video_chain *chain,
> > + struct uvc_control_mapping *mapping,
> > + struct uvc_control *ctrl,
> > + u32 v4l2_which,
> > + struct v4l2_ext_control *xctrl)
> > +{
> > + int ret;
> > + u32 flag, id;
> > +
> > + if (mapping->v4l2_type < V4L2_CTRL_COMPOUND_TYPES)
> > + return -EINVAL;
> > +
>
> This can't happen.
>
> > + switch (v4l2_which) {
> > + case V4L2_CTRL_WHICH_DEF_VAL:
> > + flag = UVC_CTRL_FLAG_GET_DEF;
> > + id = UVC_CTRL_DATA_DEF;
> > + break;
> > + case V4L2_CTRL_WHICH_MIN_VAL:
> > + flag = UVC_CTRL_FLAG_GET_MIN;
> > + id = UVC_CTRL_DATA_MIN;
> > + break;
> > + case V4L2_CTRL_WHICH_MAX_VAL:
> > + flag = UVC_CTRL_FLAG_GET_MAX;
> > + id = UVC_CTRL_DATA_MAX;
> > + break;
> > + default:
> > + return -EINVAL;
>
> Can this happen ?
>

Will remove.

> > + }
> > +
> > + if (!(ctrl->info.flags & flag) && flag != UVC_CTRL_FLAG_GET_DEF)
> > + return -EACCES;
> > +
> > + if (!ctrl->cached) {
> > + ret = uvc_ctrl_populate_cache(chain, ctrl);
> > + if (ret < 0)
> > + return ret;
> > + }
> > +
> > + return __uvc_ctrl_get_compound_to_user(mapping, ctrl, id, xctrl);
> > +}
> > +
> > int uvc_ctrl_get_fixed(struct uvc_video_chain *chain,
> > - struct v4l2_ext_control *xctrl)
> > + struct v4l2_ext_control *xctrl, u32 v4l2_which)
> > {
> > struct uvc_control *ctrl;
> > struct uvc_control_mapping *mapping;
> > - int ret;
> >
> > if (__uvc_query_v4l2_class(chain, xctrl->id, 0) >= 0)
> > return -EACCES;
> > @@ -1950,16 +2003,10 @@ int uvc_ctrl_get_fixed(struct uvc_video_chain *chain,
> > return -EINVAL;
> >
> > if (mapping->v4l2_type < V4L2_CTRL_COMPOUND_TYPES)
> > - return __uvc_ctrl_get_fixed_std(chain, xctrl);
> > + return __uvc_ctrl_get_fixed_std(chain, xctrl, v4l2_which);
> >
> > - if (!ctrl->cached) {
> > - ret = uvc_ctrl_populate_cache(chain, ctrl);
> > - if (ret < 0)
> > - return ret;
> > - }
> > -
> > - return __uvc_ctrl_get_compound_to_user(mapping, ctrl, UVC_CTRL_DATA_DEF,
> > - xctrl);
> > + return __uvc_ctrl_get_fixed_compound(chain, mapping, ctrl, v4l2_which,
> > + xctrl);
> > }
> >
> > int __uvc_ctrl_set_compound(struct uvc_control_mapping *mapping,
> > diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> > index aad61af36271..004e3b764737 100644
> > --- a/drivers/media/usb/uvc/uvc_v4l2.c
> > +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> > @@ -1043,16 +1043,21 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
> > if (ret < 0)
> > return ret;
> >
> > - if (ctrls->which == V4L2_CTRL_WHICH_DEF_VAL) {
> > + switch (ctrls->which) {
> > + case V4L2_CTRL_WHICH_DEF_VAL:
> > + case V4L2_CTRL_WHICH_MIN_VAL:
> > + case V4L2_CTRL_WHICH_MAX_VAL:
> > for (i = 0; i < ctrls->count; ++ctrl, ++i) {
> > - ret = uvc_ctrl_get_fixed(chain, ctrl);
> > + ret = uvc_ctrl_get_fixed(chain, ctrl, ctrls->which);
> > if (ret < 0) {
> > ctrls->error_idx = i;
> > return ret;
> > }
> > }
> > -
> > return 0;
> > +
> > + default:
>
> case V4L2_CTRL_WHICH_CUR_VAL:
>
> > + break;
>
> and
>
> default:
> return -EINVAL;
>
> (please double-check that the error value is the right one). This should
> be mentioned in the commit message.
>

Thanks for catching this!
What specifictly should be in the commit message? Sorry, I didn't get it.

Best,
Yunke

> > }
> >
> > ret = uvc_ctrl_begin(chain);
> > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> > index 9ff95bbad251..54cc47bc2d33 100644
> > --- a/drivers/media/usb/uvc/uvcvideo.h
> > +++ b/drivers/media/usb/uvc/uvcvideo.h
> > @@ -913,7 +913,8 @@ 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_get_fixed(struct uvc_video_chain *chain,
> > - struct v4l2_ext_control *xctrl);
> > + struct v4l2_ext_control *xctrl,
> > + u32 v4l2_which);
> > int uvc_ctrl_set(struct uvc_fh *handle, struct v4l2_ext_control *xctrl);
> > int uvc_ctrl_is_accessible(struct uvc_video_chain *chain, u32 v4l2_id,
> > bool read);
>
> --
> Regards,
>
> Laurent Pinchart