2013-04-11 21:10:46

by Steven Rostedt

[permalink] [raw]
Subject: [ 116/171 ] USB: serial: add modem-status-change wait queue stable review patch.
If anyone has any objections, please let me know.


From: Johan Hovold <[email protected]>

[ Upstream commit e5b33dc9d16053c2ae4c2c669cf008829530364b ]

Add modem-status-change wait queue to struct usb_serial_port that
subdrivers can use to implement TIOCMIWAIT.

Currently subdrivers use a private wait queue which may have been
released when waking up after device disconnected.

Note that we're adding a new wait queue rather than reusing the tty-port
one as we do not want to get woken up at hangup (yet).

Cc: stable <[email protected]>
Signed-off-by: Johan Hovold <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>
include/linux/usb/serial.h | 2 ++
1 file changed, 2 insertions(+)

diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h
index 86c0b45..0b61f01 100644
--- a/include/linux/usb/serial.h
+++ b/include/linux/usb/serial.h
@@ -66,6 +66,7 @@
* port.
* @flags: usb serial port flags
* @write_wait: a wait_queue_head_t used by the port.
+ * @delta_msr_wait: modem-status-change wait queue
* @work: work queue entry for the line discipline waking up.
* @throttled: nonzero if the read urb is inactive to throttle the device
* @throttle_req: nonzero if the tty wants to throttle us
@@ -112,6 +113,7 @@ struct usb_serial_port {

unsigned long flags;
wait_queue_head_t write_wait;
+ wait_queue_head_t delta_msr_wait;
struct work_struct work;
char throttled;
char throttle_req;