From 2200ca14df133763108b39216717e1d35b3151a0 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 26 May 2014 19:23:45 +0200 Subject: [PATCH] USB: cdc-acm: fix runtime PM imbalance at shutdown commit 5292afa657d0e790b7479ad8eef9450c1e040b3d upstream. Make sure only to decrement the PM counters if they were actually incremented. Note that the USB PM counter, but not necessarily the driver core PM counter, is reset when the interface is unbound. Fixes: 11ea859d64b6 ("USB: additional power savings for cdc-acm devices that support remote wakeup") Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman (cherry picked from commit 4421a014e97c6669db6eb8600ce83d29e5484842) Change-Id: I9038def962389acfca7f6a583e719d15f0f8d758 Signed-off-by: Neil Patel Reviewed-on: http://git-master/r/553907 GVS: Gerrit_Virtual_Submit Reviewed-by: Steve Lin --- drivers/usb/class/cdc-acm.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 6c313b1f274..dc7ed4c6a02 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -649,12 +649,13 @@ static void acm_port_shutdown(struct tty_port *port) { struct acm *acm = container_of(port, struct acm, port); int i; + int pm_err; dev_dbg(&acm->control->dev, "%s\n", __func__); mutex_lock(&acm->mutex); if (!acm->disconnected) { - usb_autopm_get_interface(acm->control); + pm_err = usb_autopm_get_interface(acm->control); acm_set_control(acm, acm->ctrlout = 0); usb_kill_urb(acm->ctrlurb); for (i = 0; i < ACM_NW; i++) @@ -662,7 +663,8 @@ static void acm_port_shutdown(struct tty_port *port) for (i = 0; i < acm->rx_buflimit; i++) usb_kill_urb(acm->read_urbs[i]); acm->control->needs_remote_wakeup = 0; - usb_autopm_put_interface(acm->control); + if (!pm_err) + usb_autopm_put_interface(acm->control); } mutex_unlock(&acm->mutex); } -- 2.39.2