diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2011-07-06 17:03:45 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-07-08 23:15:43 -0700 |
| commit | b8680d130d565da6eb07567bd6ff20b73f747498 (patch) | |
| tree | 891d92ef660465827b837900d35f1de46db1227e | |
| parent | 497bf5d2301241813317f5d66b8934ce628060a8 (diff) | |
USB: additional regression fix for device removal
commit ca5c485f55d326d9a23e4badd05890148aa53f74 upstream.
Commit e534c5b831c8b8e9f5edee5c8a37753c808b80dc (USB: fix regression
occurring during device removal) didn't go far enough. It failed to
take into account that when a driver claims multiple interfaces, it may
release them all at the same time. As a result, some interfaces can
get released before they are unregistered, and we deadlock trying to
acquire the bandwidth_mutex that we already own.
This patch (asl478) handles this case by setting the "unregistering"
flag on all the interfaces before removing any of them.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Éric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/usb/core/message.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index e0719b4ee18..0b5ec234c78 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1147,6 +1147,14 @@ void usb_disable_device(struct usb_device *dev, int skip_ep0) * any drivers bound to them (a key side effect) */ if (dev->actconfig) { + /* + * FIXME: In order to avoid self-deadlock involving the + * bandwidth_mutex, we have to mark all the interfaces + * before unregistering any of them. + */ + for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) + dev->actconfig->interface[i]->unregistering = 1; + for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) { struct usb_interface *interface; @@ -1156,7 +1164,6 @@ void usb_disable_device(struct usb_device *dev, int skip_ep0) continue; dev_dbg(&dev->dev, "unregistering interface %s\n", dev_name(&interface->dev)); - interface->unregistering = 1; remove_intf_ep_devs(interface); device_del(&interface->dev); } |