media: uvcvideo: Prevent setting unavailable flags

The addition of an extra operation to use the GET_INFO command
overwrites all existing flags from the uvc_ctrls table. This includes
setting all controls as supporting GET_MIN, GET_MAX, GET_RES, and
GET_DEF regardless of whether they do or not.

Move the initialisation of these control capabilities directly to the
uvc_ctrl_fill_xu_info() call where they were originally located in that
use case, and ensure that the new functionality in uvc_ctrl_get_flags()
will only set flags based on their reported capability from the GET_INFO
call.

Fixes: 859086ae3636 ("media: uvcvideo: Apply flags from device to actual properties")

Cc: stable@vger.kernel.org
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Tested-by: Guennadi Liakhovetski <guennadi.liakhovetski@intel.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

1 files changed, 9 insertions, 8 deletions

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 102594ec3e97..a36b4fb949fa 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1607,14 +1607,12 @@ static int uvc_ctrl_get_flags(struct uvc_device *dev,
         ret = uvc_query_ctrl(dev, UVC_GET_INFO, ctrl->entity->id, dev->intfnum,
                              info->selector, data, 1);
         if (!ret)
-                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 |= (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 ret;
@@ -1689,6 +1687,9 @@ static int uvc_ctrl_fill_xu_info(struct uvc_device *dev,
 
         info->size = le16_to_cpup((__le16 *)data);
 
+        info->flags = UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX
+                    | UVC_CTRL_FLAG_GET_RES | UVC_CTRL_FLAG_GET_DEF;
+
         ret = uvc_ctrl_get_flags(dev, ctrl, info);
         if (ret < 0) {
                 uvc_trace(UVC_TRACE_CONTROL,