[PATCH net] net: hso: fix TIOCMIWAIT race

[Johan Hovold <johan@kernel.org>]

The task state must be updated before checking the wakeup condition to
avoid missing a racing modem status update.

Fixes: 542f54823614 ("tty: Modem functions for the HSO driver")
Cc: stable@vger.kernel.org	# 2.6.29
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/net/usb/hso.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index c1aec67688ae..71caa3764b23 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -1547,10 +1547,10 @@ hso_wait_modem_status(struct hso_serial *serial, unsigned long arg)
 	spin_unlock_irq(&serial->serial_lock);
 	add_wait_queue(&tiocmget->waitq, &wait);
 	for (;;) {
+		set_current_state(TASK_INTERRUPTIBLE);
 		spin_lock_irq(&serial->serial_lock);
 		memcpy(&cnow, &tiocmget->icount, sizeof(struct uart_icount));
 		spin_unlock_irq(&serial->serial_lock);
-		set_current_state(TASK_INTERRUPTIBLE);
 		if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
 		    ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
 		    ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd))) {
-- 
2.55.0