From 5292afa657d0e790b7479ad8eef9450c1e040b3d 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 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 --- 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 eddeba61a88c..6bbd203f1861 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -590,12 +590,13 @@ static void acm_port_shutdown(struct tty_port *port) struct urb *urb; struct acm_wb *wb; 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); for (;;) { @@ -613,7 +614,8 @@ 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); } -- 2.20.1