[PATCH 3.10 33/52] USB: cdc-acm: fix runtime PM for control messages

Greg Kroah-Hartman
2014-06-24T15:52:54Z

From: Johan Hovold <jhovold@gmail.com>

commit bae3f4c53585e9a170da9436e0f06919874bda9a upstream.

Fix runtime PM handling of control messages by adding the required PM
counter operations.

Fixes: 11ea859d64b6 ("USB: additional power savings for cdc-acm devices
that support remote wakeup")

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/usb/class/cdc-acm.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -122,13 +122,23 @@ static void acm_release_minor(struct acm
static int acm_ctrl_msg(struct acm *acm, int request, int value,
void *buf, int len)
{
- int retval = usb_control_msg(acm->dev, usb_sndctrlpipe(acm->dev, 0),
+ int retval;
+
+ retval = usb_autopm_get_interface(acm->control);
+ if (retval)
+ return retval;
+
+ retval = usb_control_msg(acm->dev, usb_sndctrlpipe(acm->dev, 0),
request, USB_RT_ACM, value,
acm->control->altsetting[0].desc.bInterfaceNumber,
buf, len, 5000);
+
dev_dbg(&acm->control->dev,
"%s - rq 0x%02x, val %#x, len %#x, result %d\n",
__func__, request, value, len, retval);
+
+ usb_autopm_put_interface(acm->control);
+
return retval < 0 ? retval : 0;
}