USB: cdc_acm: Fix race condition when opening tty

If acm_rx_tasklet() gets called before tty_port_block_til_ready()
returns, then bulk IN urbs may not be sent. This fixes it.

Signed-off-by: Henry Gebhardt <gebhardt@astro.uni-tuebingen.de>
Acked-by: Oliver Neukum <oliver@neukum.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Henry Gebhardt 2009-11-04 11:19:28 +01:00 committed by Greg Kroah-Hartman
parent a1f17a872b
commit 18a77b5d23

View file

@ -609,9 +609,9 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
acm->throttle = 0;
tasklet_schedule(&acm->urb_task);
set_bit(ASYNCB_INITIALIZED, &acm->port.flags);
rv = tty_port_block_til_ready(&acm->port, tty, filp);
tasklet_schedule(&acm->urb_task);
done:
mutex_unlock(&acm->mutex);
err_out: