diff options
Diffstat (limited to 'drivers/usb/class/cdc-acm.c')
| -rw-r--r-- | drivers/usb/class/cdc-acm.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index b3e4b014a1cc..dff986021362 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -1287,9 +1287,21 @@ static int acm_probe(struct usb_interface *intf, } } } else { + int class = -1; + data_intf_num = union_header->bSlaveInterface0; control_interface = usb_ifnum_to_if(usb_dev, union_header->bMasterInterface0); data_interface = usb_ifnum_to_if(usb_dev, data_intf_num); + + if (control_interface) + class = control_interface->cur_altsetting->desc.bInterfaceClass; + + if (class != USB_CLASS_COMM && class != USB_CLASS_CDC_DATA) { + dev_dbg(&intf->dev, "Broken union descriptor, assuming single interface\n"); + combined_interfaces = 1; + control_interface = data_interface = intf; + goto look_for_collapsed_interface; + } } if (!control_interface || !data_interface) { |