@@ -443,6 +443,7 @@ static int keyspan_pda_write(struct tty_struct *tty,
int request_unthrottle = 0;
int rc = 0;
struct keyspan_pda_private *priv;
+ unsigned long flags;
priv = usb_get_serial_port_data(port);
/* guess how much room is left in the device's ring buffer, and if we
@@ -462,13 +463,13 @@ static int keyspan_pda_write(struct tty_struct *tty,
the TX urb is in-flight (wait until it completes)
the device is full (wait until it says there is room)
*/
- spin_lock_bh(&port->lock);
+ spin_lock_irqsave(&port->lock, flags);
if (!test_bit(0, &port->write_urbs_free) || priv->tx_throttled) {
- spin_unlock_bh(&port->lock);
+ spin_unlock_irqrestore(&port->lock, flags);
return 0;
}
clear_bit(0, &port->write_urbs_free);
- spin_unlock_bh(&port->lock);
+ spin_unlock_irqrestore(&port->lock, flags);
/* At this point the URB is in our control, nobody else can submit it
again (the only sudden transition was the one from EINPROGRESS to
The write() callback can be called in interrupt context (e.g. when used as a console) so interrupts must be disabled while holding the port lock to prevent a possible deadlock. Fixes: e81ee637e4ae ("usb-serial: possible irq lock inversion (PPP vs. usb/serial)") Fixes: 507ca9bc0476 ("[PATCH] USB: add ability for usb-serial drivers to determine if their write urb is currently being used.") Cc: stable <stable@vger.kernel.org> # 2.6.19 Signed-off-by: Johan Hovold <johan@kernel.org> --- drivers/usb/serial/keyspan_pda.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)