From: Oliver Neukum Date: Wed, 7 Oct 2009 07:25:10 +0000 (+0200) Subject: USB: serial: fix race between unthrottle and completion handler in opticon X-Git-Tag: v2.6.32-rc4~4^2~4 X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=88fa6590b30ef8c4d41923449ada104f915d8df8 USB: serial: fix race between unthrottle and completion handler in opticon usb:usbserial:opticon: fix race between unthrottle and completion handler opticon_unthrottle() mustn't resubmit the URB unconditionally as the URB may still be running. Signed-off-by: Oliver Neukum Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/serial/opticon.c b/drivers/usb/serial/opticon.c index 1085a57..80f59b6 100644 --- a/drivers/usb/serial/opticon.c +++ b/drivers/usb/serial/opticon.c @@ -314,21 +314,24 @@ static void opticon_unthrottle(struct tty_struct *tty) struct usb_serial_port *port = tty->driver_data; struct opticon_private *priv = usb_get_serial_data(port->serial); unsigned long flags; - int result; + int result, was_throttled; dbg("%s - port %d", __func__, port->number); spin_lock_irqsave(&priv->lock, flags); priv->throttled = false; + was_throttled = priv->actually_throttled; priv->actually_throttled = false; spin_unlock_irqrestore(&priv->lock, flags); priv->bulk_read_urb->dev = port->serial->dev; - result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC); - if (result) - dev_err(&port->dev, - "%s - failed submitting read urb, error %d\n", + if (was_throttled) { + result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC); + if (result) + dev_err(&port->dev, + "%s - failed submitting read urb, error %d\n", __func__, result); + } } static int opticon_tiocmget(struct tty_struct *tty, struct file *file)