USB: serial: inline sysrq dummy function

Inline the dummy sysrq character handling when either console support or
magic-sysrq support isn't enabled to allow the compiler to eliminate
unused code.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

drivers/usb/serial/generic.c

@@ -571,7 +571,7 @@ int usb_serial_generic_get_icount(struct tty_struct *tty,
 }
 EXPORT_SYMBOL_GPL(usb_serial_generic_get_icount);
 
-#ifdef CONFIG_MAGIC_SYSRQ
+#if defined(CONFIG_USB_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
 int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
 {
 	if (port->sysrq) {
@@ -584,13 +584,8 @@ int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
 	}
 	return 0;
 }
-#else
-int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
-{
-	return 0;
-}
-#endif
 EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
+#endif
 
 int usb_serial_handle_break(struct usb_serial_port *port)
 {

include/linux/usb/serial.h

@@ -365,8 +365,17 @@ extern int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port,
 extern void usb_serial_generic_process_read_urb(struct urb *urb);
 extern int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port,
 						void *dest, size_t size);
+
+#if defined(CONFIG_USB_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
 extern int usb_serial_handle_sysrq_char(struct usb_serial_port *port,
 					unsigned int ch);
+#else
+static inline int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
+{
+	return 0;
+}
+#endif
+
 extern int usb_serial_handle_break(struct usb_serial_port *port);
 extern void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
 					 struct tty_struct *tty,