Compound controls cannot e reliable clamped. There is plenty of space for interpretation for the device manufacturer. When we write a compound control, let the camera do the clamping and return back to the user the value used by the device. Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx> --- drivers/media/usb/uvc/uvc_ctrl.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c index 0dae5e8c3ca0..72ed7dc9cfc1 100644 --- a/drivers/media/usb/uvc/uvc_ctrl.c +++ b/drivers/media/usb/uvc/uvc_ctrl.c @@ -2339,6 +2339,18 @@ int uvc_ctrl_set(struct uvc_fh *handle, struct v4l2_ext_control *xctrl) ctrl->dirty = 1; ctrl->modified = 1; + + /* + * Compound controls cannot reliable clamp the value when they are + * written to the device. Let the device do the clamping and read back + * the value that the device is using. We do not need to return an + * error if this fails. + */ + if (uvc_ctrl_mapping_is_compound(mapping) && + uvc_ctrl_is_readable(V4L2_CTRL_WHICH_CUR_VAL, ctrl, mapping)) + uvc_mapping_get_xctrl_compound(chain, ctrl, mapping, + V4L2_CTRL_WHICH_CUR_VAL, xctrl); + return 0; } -- 2.47.0.338.g60cca15819-goog
