func: static ssize_t k90_show_current_profile(struct device struct device_attribute char *buf) int ret ; struct usb_interface * usbif = to_usb_interface ( dev -> parent ) ; struct usb_device * usbdev = interface_to_usbdev ( usbif ) ; int current_profile ; char data [ 8 ] ; ret = usb_control_msg ( usbdev , usb_rcvctrlpipe ( usbdev , 0 ) , K90_REQUEST_STATUS , USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE , 0 , 0 , data , 8 , USB_CTRL_SET_TIMEOUT ); if ( ret < 0 )  current_profile = data [ 7 ]; if ( current_profile < 1 || current_profile > 3 )  return snprintf ( buf , PAGE_SIZE , "%d\n" , current_profile ) ; 