Commit e5b33dc9 authored Mar 19, 2013 by Johan Hovold Committed by Greg Kroah-Hartman Mar 21, 2013

USB: serial: add modem-status-change wait queue



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 <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent d7971051

include/linux/usb/serial.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -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;