USB: cypress_m8: fix potential scheduling while atomic

Remove erroneous call to usb_clear_halt which is blocking and cannot be
used in interrupt context.

This code has possibly never been executed as it would cause an oops if
it was. Simply treat a stalled-endpoint error as any other error
condition.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c
index bccb1223143a37298dad934842b6733e99c38032..634f0d6605edd34063f080fcae2ad8f7b7cafe70 100644 (file)
--- a/drivers/usb/serial/cypress_m8.c
+++ b/drivers/usb/serial/cypress_m8.c
@@ -1224,7 +1224,6 @@ static void cypress_write_int_callback(struct urb *urb)
        struct usb_serial_port *port = urb->context;
        struct cypress_private *priv = usb_get_serial_port_data(port);
        struct device *dev = &urb->dev->dev;
-       int result;
        int status = urb->status;
 
        switch (status) {
@@ -1239,21 +1238,9 @@ static void cypress_write_int_callback(struct urb *urb)
                        __func__, status);
                priv->write_urb_in_use = 0;
                return;
-       case -EPIPE: /* no break needed; clear halt and resubmit */
-               if (!priv->comm_is_ok)
-                       break;
-               usb_clear_halt(port->serial->dev, 0x02);
-               /* error in the urb, so we have to resubmit it */
-               dev_dbg(dev, "%s - nonzero write bulk status received: %d\n",
-                       __func__, status);
-               port->interrupt_out_urb->transfer_buffer_length = 1;
-               result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
-               if (!result)
-                       return;
-               dev_err(dev, "%s - failed resubmitting write urb, error %d\n",
-                       __func__, result);
-               cypress_set_dead(port);
-               break;
+       case -EPIPE:
+               /* Cannot call usb_clear_halt while in_interrupt */
+               /* FALLTHROUGH */
        default:
                dev_err(dev, "%s - unexpected nonzero write status received: %d\n",
                        __func__, status);