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authorJohan Hovold <jhovold@gmail.com>2013-03-19 09:21:06 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-03-21 15:59:01 -0700
commitcb25505fc604292c70fc02143fc102f54c8595f0 (patch)
treebc648be558cdcae4376ab51ca038653ad506b3c9 /drivers/usb
parentc93d81955005c2ac0ea072f88d376026208410e1 (diff)
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USB: cdc-acm: fix device unregistration
Unregister tty device in disconnect as is required by the USB stack. By deferring unregistration to when the last tty reference is dropped, the parent interface device can get unregistered before the child resulting in broken hotplug events being generated when the tty is finally closed: KERNEL[2290.798128] remove /devices/pci0000:00/0000:00:1d.7/usb2/2-1/2-1:3.1 (usb) KERNEL[2290.804589] remove /devices/pci0000:00/0000:00:1d.7/usb2/2-1 (usb) KERNEL[2294.554799] remove /2-1:3.1/tty/ttyACM0 (tty) The driver must deal with tty callbacks after disconnect by checking the disconnected flag. Specifically, further opens must be prevented and this is already implemented. Cc: stable <stable@vger.kernel.org> Cc: Oliver Neukum <oneukum@suse.de> Acked-by: Oliver Neukum <oneukum@suse.de> Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/class/cdc-acm.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index c125b61c249..387dc6c8ad2 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -593,7 +593,6 @@ static void acm_port_destruct(struct tty_port *port)
dev_dbg(&acm->control->dev, "%s\n", __func__);
- tty_unregister_device(acm_tty_driver, acm->minor);
acm_release_minor(acm);
usb_put_intf(acm->control);
kfree(acm->country_codes);
@@ -1426,6 +1425,8 @@ static void acm_disconnect(struct usb_interface *intf)
stop_data_traffic(acm);
+ tty_unregister_device(acm_tty_driver, acm->minor);
+
usb_free_urb(acm->ctrlurb);
for (i = 0; i < ACM_NW; i++)
usb_free_urb(acm->wb[i].urb);