From: John Bauer <johnebgood@xxxxxxxxxxxxxxxx> Made recommended changes from Ricardo. I explored the case where the minimum could be > 0 but less than the maximum. If this were to occur the range of -maximum to maximum would still apply correctly however there would be a range from -min to min that would possibly not apply. It would be possible to capture the probed minimum and check against that when setting the controls. Signed-off-by: John Bauer <johnebgood@xxxxxxxxxxxxxxxx> --- drivers/media/usb/uvc/uvc_ctrl.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c index b389ab3ee05d..04300a782c81 100644 --- a/drivers/media/usb/uvc/uvc_ctrl.c +++ b/drivers/media/usb/uvc/uvc_ctrl.c @@ -1322,6 +1322,10 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain, break; } + if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MAX) + v4l2_ctrl->maximum = mapping->get(mapping, UVC_GET_MAX, + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX)); + if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MIN) { switch (v4l2_ctrl->id) { case V4L2_CID_ZOOM_CONTINUOUS: @@ -1332,8 +1336,7 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain, * value cannot be probed so it becomes the additive * inverse of maximum. */ - v4l2_ctrl->minimum = -1 * mapping->get(mapping, UVC_GET_MAX, - uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX)); + v4l2_ctrl->minimum = -v4l2_ctrl->maximum; break; default: v4l2_ctrl->minimum = mapping->get(mapping, UVC_GET_MIN, @@ -1342,10 +1345,6 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain, } } - if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MAX) - v4l2_ctrl->maximum = mapping->get(mapping, UVC_GET_MAX, - uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX)); - if (ctrl->info.flags & UVC_CTRL_FLAG_GET_RES) v4l2_ctrl->step = mapping->get(mapping, UVC_GET_RES, uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES)); @@ -1940,7 +1939,7 @@ int uvc_ctrl_set(struct uvc_fh *handle, case V4L2_CID_ZOOM_CONTINUOUS: case V4L2_CID_PAN_SPEED: case V4L2_CID_TILT_SPEED: - min = max * -1; + min = -max; default: break; } -- 2.34.1