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/aircable.c b/drivers/usb/serial/aircable.c
index 2cbfab3..b10ac84 100644
--- a/drivers/usb/serial/aircable.c
+++ b/drivers/usb/serial/aircable.c
@@ -554,13 +554,12 @@
{
struct usb_serial_port *port = tty->driver_data;
struct aircable_private *priv = usb_get_serial_port_data(port);
- unsigned long flags;
dbg("%s - port %d", __func__, port->number);
- spin_lock_irqsave(&priv->rx_lock, flags);
+ spin_lock_irq(&priv->rx_lock);
priv->rx_flags |= THROTTLED;
- spin_unlock_irqrestore(&priv->rx_lock, flags);
+ spin_unlock_irq(&priv->rx_lock);
}
/* Based on ftdi_sio.c unthrottle */
@@ -569,14 +568,13 @@
struct usb_serial_port *port = tty->driver_data;
struct aircable_private *priv = usb_get_serial_port_data(port);
int actually_throttled;
- unsigned long flags;
dbg("%s - port %d", __func__, port->number);
- spin_lock_irqsave(&priv->rx_lock, flags);
+ spin_lock_irq(&priv->rx_lock);
actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
- spin_unlock_irqrestore(&priv->rx_lock, flags);
+ spin_unlock_irq(&priv->rx_lock);
if (actually_throttled)
schedule_work(&priv->rx_work);