acm: Fix oops when closing ACM tty device right after open has failed.

This commit 10077d4a66 has stopped
checking if there was a valid acm device associated to the tty, which is
not true right after open fails and tty subsystem tries to close the
device.

As an example, open fails with a non-existing device, when probe has
never been called, because the device has never been plugged. This is
common in systems with static modules and no udev.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Thadeu Lima de Souza Cascardo 2009-06-25 14:41:30 +01:00 committed by Linus Torvalds
parent 42dd2aa649
commit 922b13565b

View File

@ -677,7 +677,7 @@ static void acm_tty_close(struct tty_struct *tty, struct file *filp)
/* Perform the closing process and see if we need to do the hardware
shutdown */
if (tty_port_close_start(&acm->port, tty, filp) == 0)
if (!acm || tty_port_close_start(&acm->port, tty, filp) == 0)
return;
acm_port_down(acm, 0);
tty_port_close_end(&acm->port, tty);