serial: doc: .(un)throttle() are serialized by the tty layer
Document that .(un)throttle() are serialized with each other, and with
termios modification by the tty layer.
Reported-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/serial/driver b/Documentation/serial/driver
index 03b703c..7fb80682e 100644
--- a/Documentation/serial/driver
+++ b/Documentation/serial/driver
@@ -137,7 +137,8 @@
should be sent to the serial port.
This will be called only if hardware assisted flow control is enabled.
- Locking: none.
+ Locking: serialized with .unthrottle() and termios modification by the
+ tty layer.
unthrottle(port)
Notify the serial driver that characters can now be sent to the serial
@@ -145,7 +146,8 @@
disciplines.
This will be called only if hardware assisted flow control is enabled.
- Locking: none.
+ Locking: serialized with .throttle() and termios modification by the
+ tty layer.
send_xchar(port,ch)
Transmit a high priority character, even if the port is stopped.