diff options
| author | Oliver Neukum <oliver@neukum.org> | 2009-10-07 10:50:23 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-10-09 22:52:09 +0200 |
| commit | 638325154572ba2113a18669fe3b299caa2dabd9 (patch) | |
| tree | c562a8460be432facbbba11288edaceba5ecbf1c /drivers/usb/serial/cypress_m8.c | |
| parent | USB: serial: fix race between unthrottle and completion handler in symbolserial (diff) | |
| download | linux-638325154572ba2113a18669fe3b299caa2dabd9.tar.xz linux-638325154572ba2113a18669fe3b299caa2dabd9.zip | |
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>
Diffstat (limited to 'drivers/usb/serial/cypress_m8.c')
| -rw-r--r-- | drivers/usb/serial/cypress_m8.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c index e0a8b715f2f2..a591ebec0f89 100644 --- a/drivers/usb/serial/cypress_m8.c +++ b/drivers/usb/serial/cypress_m8.c @@ -1155,13 +1155,12 @@ static void cypress_throttle(struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; struct cypress_private *priv = usb_get_serial_port_data(port); - unsigned long flags; dbg("%s - port %d", __func__, port->number); - spin_lock_irqsave(&priv->lock, flags); + spin_lock_irq(&priv->lock); priv->rx_flags = THROTTLED; - spin_unlock_irqrestore(&priv->lock, flags); + spin_unlock_irq(&priv->lock); } @@ -1170,14 +1169,13 @@ static void cypress_unthrottle(struct tty_struct *tty) struct usb_serial_port *port = tty->driver_data; struct cypress_private *priv = usb_get_serial_port_data(port); int actually_throttled, result; - unsigned long flags; dbg("%s - port %d", __func__, port->number); - spin_lock_irqsave(&priv->lock, flags); + spin_lock_irq(&priv->lock); actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED; priv->rx_flags = 0; - spin_unlock_irqrestore(&priv->lock, flags); + spin_unlock_irq(&priv->lock); if (!priv->comm_is_ok) return; @@ -1185,7 +1183,7 @@ static void cypress_unthrottle(struct tty_struct *tty) if (actually_throttled) { port->interrupt_in_urb->dev = port->serial->dev; - result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC); + result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL); if (result) { dev_err(&port->dev, "%s - failed submitting read urb, " "error %d\n", __func__, result); |