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authorJohan Hovold <jhovold@gmail.com>2014-05-26 19:23:45 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-06-26 15:10:29 -0400
commit7be9d6cd4b57ebd5b344e4a006c0aa6e7a08aba3 (patch)
treeae3b4a8e437859265f2458d1b3b54d25acab18e6
parent8fd20d5a377f5baa510a804a3b2c9b21d31bb445 (diff)
downloadlinux-linaro-stable-7be9d6cd4b57ebd5b344e4a006c0aa6e7a08aba3.tar.gz
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 <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/class/cdc-acm.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 7ffd5f55738d..2f2540ff21f6 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -623,12 +623,13 @@ 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 (;;) {
@@ -646,7 +647,8 @@ 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);
}