Hi Edgar, Thanks for addressing my concerns in this updated patch. On 12/10/17 08:54, Edgar Thier wrote: > > Use flags the device exposes for UVC controls. > This allows the device to define which property flags are set. > > Since some cameras offer auto-adjustments for properties (e.g. auto-gain), > the values of other properties (e.g. gain) can change in the camera. > Examining the flags ensures that the driver is aware of such properties. > > Signed-off-by: Edgar Thier <info@xxxxxxxxxxxxxx> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx> > --- > drivers/media/usb/uvc/uvc_ctrl.c | 64 ++++++++++++++++++++++++++++++---------- > 1 file changed, 49 insertions(+), 15 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c > index 20397aba..8f902a41 100644 > --- a/drivers/media/usb/uvc/uvc_ctrl.c > +++ b/drivers/media/usb/uvc/uvc_ctrl.c > @@ -1629,6 +1629,40 @@ static void uvc_ctrl_fixup_xu_info(struct uvc_device *dev, > } > } > > +/* > + * Retrieve flags for a given control > + */ > +static int uvc_ctrl_get_flags(struct uvc_device *dev, const struct uvc_control *ctrl, > + const struct uvc_control_info *info) > +{ > + u8 *data; > + int ret = 0; > + int flags = 0; > + > + data = kmalloc(2, GFP_KERNEL); > + if (data == NULL) > + return -ENOMEM; > + > + ret = uvc_query_ctrl(dev, UVC_GET_INFO, ctrl->entity->id, dev->intfnum, > + info->selector, data, 1); > + if (ret < 0) { > + uvc_trace(UVC_TRACE_CONTROL, > + "GET_INFO failed on control %pUl/%u (%d).\n", > + info->entity, info->selector, ret); > + } else { > + flags = UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX > + | UVC_CTRL_FLAG_GET_RES | UVC_CTRL_FLAG_GET_DEF > + | (data[0] & UVC_CONTROL_CAP_GET ? > + UVC_CTRL_FLAG_GET_CUR : 0) > + | (data[0] & UVC_CONTROL_CAP_SET ? > + UVC_CTRL_FLAG_SET_CUR : 0) > + | (data[0] & UVC_CONTROL_CAP_AUTOUPDATE ? > + UVC_CTRL_FLAG_AUTO_UPDATE : 0); > + } > + kfree(data); > + return flags; > +} > + > /* > * Query control information (size and flags) for XU controls. > */ > @@ -1636,6 +1670,7 @@ static int uvc_ctrl_fill_xu_info(struct uvc_device *dev, > const struct uvc_control *ctrl, struct uvc_control_info *info) > { > u8 *data; > + int flags; > int ret; > > data = kmalloc(2, GFP_KERNEL); > @@ -1659,24 +1694,15 @@ static int uvc_ctrl_fill_xu_info(struct uvc_device *dev, > > info->size = le16_to_cpup((__le16 *)data); > > - /* Query the control information (GET_INFO) */ > - ret = uvc_query_ctrl(dev, UVC_GET_INFO, ctrl->entity->id, dev->intfnum, > - info->selector, data, 1); > - if (ret < 0) { > + flags = uvc_ctrl_get_flags(dev, ctrl, info); > + > + if (flags < 0) { > uvc_trace(UVC_TRACE_CONTROL, > - "GET_INFO failed on control %pUl/%u (%d).\n", > - info->entity, info->selector, ret); > + "Failed to retrieve flags (%d).\n", ret); > + ret = flags; > goto done; > } > - > - info->flags = UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX > - | UVC_CTRL_FLAG_GET_RES | UVC_CTRL_FLAG_GET_DEF > - | (data[0] & UVC_CONTROL_CAP_GET ? > - UVC_CTRL_FLAG_GET_CUR : 0) > - | (data[0] & UVC_CONTROL_CAP_SET ? > - UVC_CTRL_FLAG_SET_CUR : 0) > - | (data[0] & UVC_CONTROL_CAP_AUTOUPDATE ? > - UVC_CTRL_FLAG_AUTO_UPDATE : 0); > + info->flags = flags; > > uvc_ctrl_fixup_xu_info(dev, ctrl, info); > > @@ -1890,6 +1916,7 @@ static int uvc_ctrl_add_info(struct uvc_device *dev, struct uvc_control *ctrl, > const struct uvc_control_info *info) > { > int ret = 0; > + int flags = 0; > > ctrl->info = *info; > INIT_LIST_HEAD(&ctrl->info.mappings); > @@ -1902,6 +1929,13 @@ static int uvc_ctrl_add_info(struct uvc_device *dev, struct uvc_control *ctrl, > goto done; > } > > + flags = uvc_ctrl_get_flags(dev, ctrl, info); > + if (flags < 0) > + uvc_trace(UVC_TRACE_CONTROL, > + "Failed to retrieve flags (%d).\n", ret); > + else > + ctrl->info.flags = flags; > + > ctrl->initialized = 1; > > uvc_trace(UVC_TRACE_CONTROL, "Added control %pUl/%u to device %s " >