From: Johan Hovold <jhovold@gmail.com>
Date: Mon, 26 May 2014 17:23:32 +0000 (+0200)
Subject: USB: usb_wwan: do not resume I/O on closing ports
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=b0a9aa6da8088b722326a858ab572a13b5b6f9cb;p=openwrt%2Fstaging%2Fblogic.git

USB: usb_wwan: do not resume I/O on closing ports

Use tty-port initialised flag rather than private flag to determine when
port is closing down.

Since the tty-port flag is set prior to dropping DTR/RTS (when HUPCL is
set) this avoid submitting the read urbs when resuming the interface in
dtr_rts() only to immediately kill them again in shutdown().

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

diff --git a/drivers/usb/serial/usb-wwan.h b/drivers/usb/serial/usb-wwan.h
index 8502f9add334..f22dff58b587 100644
--- a/drivers/usb/serial/usb-wwan.h
+++ b/drivers/usb/serial/usb-wwan.h
@@ -48,7 +48,6 @@ struct usb_wwan_port_private {
 	struct urb *out_urbs[N_OUT_URB];
 	u8 *out_buffer[N_OUT_URB];
 	unsigned long out_busy;	/* Bit vector of URBs in use */
-	int opened;
 	struct usb_anchor delayed;
 
 	/* Settings for the port */
diff --git a/drivers/usb/serial/usb_wwan.c b/drivers/usb/serial/usb_wwan.c
index bbcbdaa16c17..2932d9cfb166 100644
--- a/drivers/usb/serial/usb_wwan.c
+++ b/drivers/usb/serial/usb_wwan.c
@@ -395,7 +395,6 @@ int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port)
 	}
 
 	spin_lock_irq(&intfdata->susp_lock);
-	portdata->opened = 1;
 	if (++intfdata->open_ports == 1)
 		serial->interface->needs_remote_wakeup = 1;
 	spin_unlock_irq(&intfdata->susp_lock);
@@ -429,8 +428,11 @@ void usb_wwan_close(struct usb_serial_port *port)
 
 	portdata = usb_get_serial_port_data(port);
 
+	/*
+	 * Need to take susp_lock to make sure port is not already being
+	 * resumed, but no need to hold it due to ASYNC_INITIALIZED.
+	 */
 	spin_lock_irq(&intfdata->susp_lock);
-	portdata->opened = 0;
 	if (--intfdata->open_ports == 0)
 		serial->interface->needs_remote_wakeup = 0;
 	spin_unlock_irq(&intfdata->susp_lock);
@@ -645,11 +647,12 @@ int usb_wwan_resume(struct usb_serial *serial)
 	spin_lock_irq(&intfdata->susp_lock);
 	for (i = 0; i < serial->num_ports; i++) {
 		port = serial->port[i];
-		portdata = usb_get_serial_port_data(port);
 
-		if (!portdata || !portdata->opened)
+		if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags))
 			continue;
 
+		portdata = usb_get_serial_port_data(port);
+
 		if (port->interrupt_in_urb) {
 			err = usb_submit_urb(port->interrupt_in_urb,
 					GFP_ATOMIC);