From 8fdbeb26b5105282e55559b54a660fe7b6eed331 Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum@suse.de>
Date: Wed, 20 Nov 2013 11:35:36 +0100
Subject: [PATCH] cdc-acm: fix power management in ioctl
An ioctl that does depends on communication with a device should
prevent suspension of teh device.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/class/cdc-acm.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 92e28ecda83459..8fe32eb7970e90 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -888,7 +888,13 @@ static int acm_tty_ioctl(struct tty_struct *tty,
rv = set_serial_info(acm, (struct serial_struct __user *) arg);
break;
case TIOCMIWAIT:
+ rv = usb_autopm_get_interface(acm->control);
+ if (rv < 0) {
+ rv = -EIO;
+ break;
+ }
rv = wait_serial_change(acm, arg);
+ usb_autopm_put_interface(acm->control);
break;
case TIOCGICOUNT:
rv = get_serial_usage(acm, (struct serial_icounter_struct __user *) arg);
--
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