[PATCH 3.16 203/370] USB: serial: ch341: fix resume after reset

Ben Hutchings
2017-03-10T12:23:48Z

From: Johan Hovold <johan@kernel.org>

commit ce5e292828117d1b71cbd3edf9e9137cf31acd30 upstream.

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")
Signed-off-by: Johan Hovold <johan@kernel.org>
[bwh: Backported to 3.16: open-code tty_port_initialized()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/usb/serial/ch341.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)

--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -559,14 +559,23 @@ static int ch341_tiocmget(struct tty_str

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 (port->port.flags & ASYNC_INITIALIZED) {
+ 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 = {