From: Peter Hurley <peter@hurleysoftware.com>
Date: Tue, 2 Sep 2014 21:39:20 +0000 (-0400)
Subject: serial: 8250: Document serial8250_modem_status() locking
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=5435d20f506f16352a4e1637b8e8fb7c0d422bb9;p=linux-beck.git

serial: 8250: Document serial8250_modem_status() locking

Existing callers of serial8250_modem_status() [1] hold the uart port
lock; document.

[1] In-tree callers of serial8250_modem_status()

drivers/tty/serial/8250/8250_fsl.c
  fsl8250_handle_irq()

drivers/tty/serial/8250/8250_core.c
  serial8250_handle_irq()
  serial8250_console_write()
  serial8250_get_mctrl() *

* Call graphs for callers of serial8250_get_mctrl() from the function
  which acquires the uart port lock

drivers/tty/serial/serial_core.c
  uart_port_startup()
  uart_tiocmget()
  uart_set_termios()
  uart_carrier_raised()
    ops->get_mctrl() ---> serial8250_get_mctrl()

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 46c1f5fc44d3..b597e730b9e7 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -1463,6 +1463,7 @@ void serial8250_tx_chars(struct uart_8250_port *up)
 }
 EXPORT_SYMBOL_GPL(serial8250_tx_chars);
 
+/* Caller holds uart port lock */
 unsigned int serial8250_modem_status(struct uart_8250_port *up)
 {
 	struct uart_port *port = &up->port;