hso: fix soft-lockup

Fix soft-lockup in hso.c which is triggered on SMP machine when
modem is removed while file descriptor(s) under /dev are still open:

  old version called kref_put() too early which resulted in destroying
  hso_serial and hso_device objects which were still used later on.

Signed-off-by: Antti Kaijanmäki <antti.kaijanmaki@nomovok.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Antti Kaijanmäki 2009-11-23 10:54:47 -08:00 committed by David S. Miller
parent 9ce673d5e9
commit dcfcb256cc

View File

@ -1363,7 +1363,7 @@ static void hso_serial_close(struct tty_struct *tty, struct file *filp)
/* reset the rts and dtr */
/* do the actual close */
serial->open_count--;
kref_put(&serial->parent->ref, hso_serial_ref_free);
if (serial->open_count <= 0) {
serial->open_count = 0;
spin_lock_irq(&serial->serial_lock);
@ -1383,6 +1383,8 @@ static void hso_serial_close(struct tty_struct *tty, struct file *filp)
usb_autopm_put_interface(serial->parent->interface);
mutex_unlock(&serial->parent->mutex);
kref_put(&serial->parent->ref, hso_serial_ref_free);
}
/* close the requested serial port */