From b2a5cf1bdc011f5474c72543f9d8116c0f07f452 Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oliver@neukum.org>
Date: Wed, 7 Oct 2009 09:30:49 +0200
Subject: [PATCH] USB: serial: fix race between unthrottle and completion
handler in symbolserial
usb:usbserial:symbolserial: fix race between unthrottle and completion handler
symbol_unthrottle() mustn't resubmit the URB unconditionally
as the URB may still be running.
the same bug as opticon.
Signed-off-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/usb/serial/symbolserial.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/serial/symbolserial.c b/drivers/usb/serial/symbolserial.c
index cb7e95f9fcbf5..f25e545268434 100644
--- a/drivers/usb/serial/symbolserial.c
+++ b/drivers/usb/serial/symbolserial.c
@@ -179,20 +179,24 @@ static void symbol_unthrottle(struct tty_struct *tty)
struct symbol_private *priv = usb_get_serial_data(port->serial);
unsigned long flags;
int result;
+ bool 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->int_urb->dev = port->serial->dev;
- result = usb_submit_urb(priv->int_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->int_urb, GFP_ATOMIC);
+ if (result)
+ dev_err(&port->dev,
+ "%s - failed submitting read urb, error %d\n",
__func__, result);
+ }
}
static int symbol_startup(struct usb_serial *serial)
--
2.30.2