USB: usbserial - fix potential deadlock between write() and IRQ

[karo-tx-linux.git] / drivers / usb / serial / generic.c

diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
index 88a2c7dce335f9b1cde151ae457bf1d55054132d..9eb4a65ee4d9943026f74de49c4e3013c8f3f65f 100644 (file)
--- a/drivers/usb/serial/generic.c
+++ b/drivers/usb/serial/generic.c
@@ -208,14 +208,15 @@ int usb_serial_generic_write(struct usb_serial_port *port, const unsigned char *
 
        /* only do something if we have a bulk out endpoint */
        if (serial->num_bulk_out) {
-               spin_lock_bh(&port->lock);
+               unsigned long flags;
+               spin_lock_irqsave(&port->lock, flags);
                if (port->write_urb_busy) {
-                       spin_unlock_bh(&port->lock);
+                       spin_unlock_irqrestore(&port->lock, flags);
                        dbg("%s - already writing", __FUNCTION__);
                        return 0;
                }
                port->write_urb_busy = 1;
-               spin_unlock_bh(&port->lock);
+               spin_unlock_irqrestore(&port->lock, flags);
 
                count = (count > port->bulk_out_size) ? port->bulk_out_size : count;