USB: suspend/resume support for option driver

This patch implements suspend and resume methods for the
option driver. With my hardware I can even suspend the system
and keep up a connection for a short time.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-Off-By: Matthias Urlichs <smurf@smurf.noris.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/option.c

@@ -62,6 +62,8 @@ static int  option_tiocmget(struct tty_struct *tty, struct file *file);
 static int  option_tiocmset(struct tty_struct *tty, struct file *file,
 				unsigned int set, unsigned int clear);
 static int  option_send_setup(struct tty_struct *tty, struct usb_serial_port *port);
+static int  option_suspend(struct usb_serial *serial, pm_message_t message);
+static int  option_resume(struct usb_serial *serial);
 
 /* Vendor and product IDs */
 #define OPTION_VENDOR_ID			0x0AF0
@@ -523,6 +525,8 @@ static struct usb_driver option_driver = {
 	.name       = "option",
 	.probe      = usb_serial_probe,
 	.disconnect = usb_serial_disconnect,
+	.suspend    = usb_serial_suspend,
+	.resume     = usb_serial_resume,
 	.id_table   = option_ids,
 	.no_dynamic_id = 	1,
 };
@@ -551,6 +555,8 @@ static struct usb_serial_driver option_1port_device = {
 	.attach            = option_startup,
 	.shutdown          = option_shutdown,
 	.read_int_callback = option_instat_callback,
+	.suspend           = option_suspend,
+	.resume            = option_resume,
 };
 
 static int debug;
@@ -821,10 +827,10 @@ static void option_instat_callback(struct urb *urb)
 				req_pkt->bRequestType, req_pkt->bRequest);
 		}
 	} else
-		dbg("%s: error %d", __func__, status);
+		err("%s: error %d", __func__, status);
 
 	/* Resubmit urb so we continue receiving IRQ data */
-	if (status != -ESHUTDOWN) {
+	if (status != -ESHUTDOWN && status != -ENOENT) {
 		urb->dev = serial->dev;
 		err = usb_submit_urb(urb, GFP_ATOMIC);
 		if (err)
@@ -843,7 +849,6 @@ static int option_write_room(struct tty_struct *tty)
 
 	portdata = usb_get_serial_port_data(port);
 
-
 	for (i = 0; i < N_OUT_URB; i++) {
 		this_urb = portdata->out_urbs[i];
 		if (this_urb && !test_bit(i, &portdata->out_busy))
@@ -1105,14 +1110,12 @@ static int option_startup(struct usb_serial *serial)
 	return 1;
 }
 
-static void option_shutdown(struct usb_serial *serial)
+static void stop_read_write_urbs(struct usb_serial *serial)
 {
 	int i, j;
 	struct usb_serial_port *port;
 	struct option_port_private *portdata;
 
-	dbg("%s", __func__);
-
 	/* Stop reading/writing urbs */
 	for (i = 0; i < serial->num_ports; ++i) {
 		port = serial->port[i];
@@ -1122,6 +1125,17 @@ static void option_shutdown(struct usb_serial *serial)
 		for (j = 0; j < N_OUT_URB; j++)
 			usb_kill_urb(portdata->out_urbs[j]);
 	}
+}
+
+static void option_shutdown(struct usb_serial *serial)
+{
+	int i, j;
+	struct usb_serial_port *port;
+	struct option_port_private *portdata;
+
+	dbg("%s", __func__);
+
+	stop_read_write_urbs(serial);
 
 	/* Now free them */
 	for (i = 0; i < serial->num_ports; ++i) {
@@ -1152,6 +1166,66 @@ static void option_shutdown(struct usb_serial *serial)
 	}
 }
 
+static int option_suspend(struct usb_serial *serial, pm_message_t message)
+{
+	dbg("%s entered", __func__);
+	stop_read_write_urbs(serial);
+
+	return 0;
+}
+
+static int option_resume(struct usb_serial *serial)
+{
+	int err, i, j;
+	struct usb_serial_port *port;
+	struct urb *urb;
+	struct option_port_private *portdata;
+
+	dbg("%s entered", __func__);
+	/* get the interrupt URBs resubmitted unconditionally */
+	for (i = 0; i < serial->num_ports; i++) {
+		port = serial->port[i];
+		if (!port->interrupt_in_urb) {
+			dbg("%s: No interrupt URB for port %d\n", __func__, i);
+			continue;
+		}
+		port->interrupt_in_urb->dev = serial->dev;
+		err = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
+		dbg("Submitted interrupt URB for port %d (result %d)", i, err);
+		if (err < 0) {
+			err("%s: Error %d for interrupt URB of port%d",
+				 __func__, err, i);
+			return err;
+		}
+	}
+
+	for (i = 0; i < serial->num_ports; i++) {
+		/* walk all ports */
+		port = serial->port[i];
+		portdata = usb_get_serial_port_data(port);
+		mutex_lock(&port->mutex);
+
+		/* skip closed ports */
+		if (!port->port.count) {
+			mutex_unlock(&port->mutex);
+			continue;
+		}
+
+		for (j = 0; j < N_IN_URB; j++) {
+			urb = portdata->in_urbs[j];
+			err = usb_submit_urb(urb, GFP_NOIO);
+			if (err < 0) {
+				mutex_unlock(&port->mutex);
+				err("%s: Error %d for bulk URB %d",
+					 __func__, err, i);
+				return err;
+			}
+		}
+		mutex_unlock(&port->mutex);
+	}
+	return 0;
+}
+
 MODULE_AUTHOR(DRIVER_AUTHOR);
 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_VERSION(DRIVER_VERSION);