USB: serial: fix assumption that throttle/unthrottle cannot sleep
many serial subdrivers are clearly written as if throttle/unthrottle
cannot sleep. This leads to unneeded atomic submissions. This
patch converts affected drivers in a way to makes very clear that
throttle/unthrottle can sleep. Thus future misdesigns can be avoided
and efficiency and reliability improved.
This removes any such assumption using GFP_KERNEL and spin_lock_irq()
Signed-off-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/serial/symbolserial.c b/drivers/usb/serial/symbolserial.c
index f25e545..b282c0f 100644
--- a/drivers/usb/serial/symbolserial.c
+++ b/drivers/usb/serial/symbolserial.c
@@ -165,33 +165,31 @@
{
struct usb_serial_port *port = tty->driver_data;
struct symbol_private *priv = usb_get_serial_data(port->serial);
- unsigned long flags;
dbg("%s - port %d", __func__, port->number);
- spin_lock_irqsave(&priv->lock, flags);
+ spin_lock_irq(&priv->lock);
priv->throttled = true;
- spin_unlock_irqrestore(&priv->lock, flags);
+ spin_unlock_irq(&priv->lock);
}
static void symbol_unthrottle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
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);
+ spin_lock_irq(&priv->lock);
priv->throttled = false;
was_throttled = priv->actually_throttled;
priv->actually_throttled = false;
- spin_unlock_irqrestore(&priv->lock, flags);
+ spin_unlock_irq(&priv->lock);
priv->int_urb->dev = port->serial->dev;
if (was_throttled) {
- result = usb_submit_urb(priv->int_urb, GFP_ATOMIC);
+ result = usb_submit_urb(priv->int_urb, GFP_KERNEL);
if (result)
dev_err(&port->dev,
"%s - failed submitting read urb, error %d\n",