Hi Hans On Mon, Mar 22, 2021 at 1:06 PM Hans Verkuil <hverkuil@xxxxxxxxx> wrote: > > Check for inactive controls in uvc_ctrl_is_accessible(). > Use the new value for the master_id controls if present, > otherwise use the existing value to determine if it is OK > to set the control. Doing this here avoids attempting to > set an inactive control, which will return an error from the > USB device. Dont you think that this patch is not needed if this is used: https://patchwork.linuxtv.org/project/linux-media/patch/20210319170906.278238-17-ribalda@xxxxxxxxxxxx/ ? Also Maybe it is wrong. (Maybe it is the keyword here ;). I think the initial assumption was that uvc_ctrl_is_accessible shall not access the hardware, but with this patch it is accessing it. > > Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> > --- > Ricardo: this can be added to your uvc series. It avoids attempts to set > inactive controls. > --- > drivers/media/usb/uvc/uvc_ctrl.c | 28 +++++++++++++++++++++++++++- > drivers/media/usb/uvc/uvc_v4l2.c | 4 ++-- > drivers/media/usb/uvc/uvcvideo.h | 3 ++- > 3 files changed, 31 insertions(+), 4 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c > index d9d4add1e813..6e7b904bc33d 100644 > --- a/drivers/media/usb/uvc/uvc_ctrl.c > +++ b/drivers/media/usb/uvc/uvc_ctrl.c > @@ -1047,10 +1047,18 @@ static int uvc_query_v4l2_class(struct uvc_video_chain *chain, u32 req_id, > } > > int uvc_ctrl_is_accessible(struct uvc_video_chain *chain, u32 v4l2_id, > - bool read) > + const struct v4l2_ext_controls *ctrls, > + unsigned long ioctl) > { > + struct uvc_control_mapping *master_map = NULL; > + struct uvc_control *master_ctrl = NULL; > struct uvc_control_mapping *mapping; > struct uvc_control *ctrl; > + bool read = ioctl == VIDIOC_G_EXT_CTRLS; > + bool try = ioctl == VIDIOC_TRY_EXT_CTRLS; > + s32 val; > + int ret; > + int i; > > if (__uvc_query_v4l2_class(chain, v4l2_id, 0) >= 0) > return -EACCES; > @@ -1065,6 +1073,24 @@ int uvc_ctrl_is_accessible(struct uvc_video_chain *chain, u32 v4l2_id, > if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR) && !read) > return -EACCES; > > + if (read || try || !mapping->master_id) > + return 0; > + > + for (i = ctrls->count - 1; i >= 0; i--) > + if (ctrls->controls[i].id == mapping->master_id) > + return ctrls->controls[i].value == > + mapping->master_manual ? 0 : -EACCES; > + > + __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 0; > + > + ret = __uvc_ctrl_get(chain, master_ctrl, master_map, &val); > + if (ret >= 0 && val != mapping->master_manual) > + return -EACCES; > + > return 0; > } > > diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c > index 12362e0f9870..e40db7ae18b1 100644 > --- a/drivers/media/usb/uvc/uvc_v4l2.c > +++ b/drivers/media/usb/uvc/uvc_v4l2.c > @@ -803,8 +803,8 @@ 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_accessible(chain, ctrl->id, > - ioctl == VIDIOC_G_EXT_CTRLS); > + ret = uvc_ctrl_is_accessible(chain, ctrl->id, ctrls, > + ioctl); > if (ret) > break; > } > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h > index aedb4d3d4db9..8849d7953767 100644 > --- a/drivers/media/usb/uvc/uvcvideo.h > +++ b/drivers/media/usb/uvc/uvcvideo.h > @@ -869,7 +869,8 @@ 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_accessible(struct uvc_video_chain *chain, u32 v4l2_id, > - bool read); > + const struct v4l2_ext_controls *ctrls, > + unsigned long ioctl); > > int uvc_xu_ctrl_query(struct uvc_video_chain *chain, > struct uvc_xu_control_query *xqry); > -- > 2.30.0 > > -- Ricardo Ribalda
