USB: don't register endpoints for interfaces that are going away
This patch (as1155) fixes a bug in usbcore. When interfaces are
deleted, either because the device was disconnected or because of a
configuration change, the extra attribute files and child endpoint
devices may get left behind. This is because the core removes them
before calling device_del(). But during device_del(), after the
driver is unbound the core will reinstall altsetting 0 and recreate
those extra attributes and children.
The patch prevents this by adding a flag to record when the interface
is in the midst of being unregistered. When the flag is set, the
attribute files and child devices will not be created.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org> [2.6.27, 2.6.26, 2.6.25]
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 8877385..6d1048f 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1091,6 +1091,7 @@
continue;
dev_dbg(&dev->dev, "unregistering interface %s\n",
dev_name(&interface->dev));
+ interface->unregistering = 1;
usb_remove_sysfs_intf_files(interface);
device_del(&interface->dev);
}
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index f66fba1..4fb65fd 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -840,7 +840,7 @@
struct usb_host_interface *alt = intf->cur_altsetting;
int retval;
- if (intf->sysfs_files_created)
+ if (intf->sysfs_files_created || intf->unregistering)
return 0;
/* The interface string may be present in some altsettings
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 8fa973b..f72aa51 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -108,6 +108,7 @@
* (in probe()), bound to a driver, or unbinding (in disconnect())
* @is_active: flag set when the interface is bound and not suspended.
* @sysfs_files_created: sysfs attributes exist
+ * @unregistering: flag set when the interface is being unregistered
* @needs_remote_wakeup: flag set when the driver requires remote-wakeup
* capability during autosuspend.
* @needs_altsetting0: flag set when a set-interface request for altsetting 0
@@ -163,6 +164,7 @@
enum usb_interface_condition condition; /* state of binding */
unsigned is_active:1; /* the interface is not suspended */
unsigned sysfs_files_created:1; /* the sysfs attributes exist */
+ unsigned unregistering:1; /* unregistration is in progress */
unsigned needs_remote_wakeup:1; /* driver requires remote wakeup */
unsigned needs_altsetting0:1; /* switch to altsetting 0 is pending */
unsigned needs_binding:1; /* needs delayed unbind/rebind */