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>
diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index 746839b..43bc3fc 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -1363,7 +1363,7 @@
/* 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 @@
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 */