@@ -98,13 +98,19 @@ static int usb_serial_device_remove(struct device *dev)
struct usb_serial_port *port;
int retval = 0;
int minor;
+ int autopm_err;
port = to_usb_serial_port(dev);
if (!port)
return -ENODEV;
- /* make sure suspend/resume doesn't race against port_remove */
- usb_autopm_get_interface(port->serial->interface);
+ /*
+ * Make sure suspend/resume doesn't race against port_remove.
+ *
+ * Note that no further runtime PM callbacks will be made if
+ * autopm_get fails.
+ */
+ autopm_err = usb_autopm_get_interface(port->serial->interface);
minor = port->minor;
tty_unregister_device(usb_serial_tty_driver, minor);
@@ -118,7 +124,9 @@ static int usb_serial_device_remove(struct device *dev)
dev_info(dev, "%s converter now disconnected from ttyUSB%d\n",
driver->description, minor);
- usb_autopm_put_interface(port->serial->interface);
+ if (!autopm_err)
+ usb_autopm_put_interface(port->serial->interface);
+
return retval;
}
This is a note to let you know that I have just added a patch titled USB: serial: fix potential runtime pm imbalance at device remove to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.11.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 3e54da27d50bd962ebbdb0dc359f358018a4e03a Mon Sep 17 00:00:00 2001 From: Johan Hovold <jhovold@gmail.com> Date: Mon, 26 May 2014 19:23:33 +0200 Subject: USB: serial: fix potential runtime pm imbalance at device remove commit c14829fad88dbeda57253590695b85ba51270621 upstream. Only call usb_autopm_put_interface() if the corresponding usb_autopm_get_interface() was successful. This prevents a potential runtime PM counter imbalance should usb_autopm_get_interface() fail. Note that the USB PM usage counter is reset when the interface is unbound, but that the runtime PM counter may be left unbalanced. Also add comment on why we don't need to worry about racing resume/suspend on autopm_get failures. Fixes: d5fd650cfc7f ("usb: serial: prevent suspend/resume from racing against probe/remove") Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/usb/serial/bus.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) -- 1.9.1