USB: serial: ch341: fix resume after reset

Fix reset-resume handling which failed to resubmit the read and
interrupt URBs, thereby leaving a port that was open before suspend in a
broken state until closed and reopened.

Fixes: 1ded7ea47b88 ("USB: ch341 serial: fix port number changed after
resume")
Fixes: 2bfd1c96a9fb ("USB: serial: ch341: remove reset_resume callback")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

1 files changed, 13 insertions, 4 deletions

diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index 8f41d4385f1c..5343d65f3b52 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -582,14 +582,23 @@ static int ch341_tiocmget(struct tty_struct *tty)
 
 static int ch341_reset_resume(struct usb_serial *serial)
 {
-        struct ch341_private *priv;
-
-        priv = usb_get_serial_port_data(serial->port[0]);
+        struct usb_serial_port *port = serial->port[0];
+        struct ch341_private *priv = usb_get_serial_port_data(port);
+        int ret;
 
         /* reconfigure ch341 serial port after bus-reset */
         ch341_configure(serial->dev, priv);
 
-        return 0;
+        if (tty_port_initialized(&port->port)) {
+                ret = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
+                if (ret) {
+                        dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
+                                ret);
+                        return ret;
+                }
+        }
+
+        return usb_serial_generic_resume(serial);
 }
 
 static struct usb_serial_driver ch341_device = {