Messages in this thread | | | Subject | Re: [PATCH] Bluetooth: postpone hci_dev unregistration | From | Marcel Holtmann <> | Date | Fri, 04 May 2007 08:41:53 +0200 |
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Hi Jiri,
> (I sent this a week ago but it seems to have got lost in other noise, > resending) > > From: Jiri Kosina <jkosina@suse.cz> > > Bluetooth: postpone hci_dev unregistration > > Commit b40df57 substituted bh_lock_sock() in hci_sock_dev_event() for > lock_sock() when unregistering HCI device, in order to prevent deadlock > against locking in l2cap_connect_cfm() from softirq context. > > This however introduces another problem - hci_sock_dev_event() for > HCI_DEV_UNREG can also be triggered in atomic context, in which calling > lock_sock() is not safe as it could sleep. Reported by Jeremy Fitzhardinge > at http://lkml.org/lkml/2007/4/23/271 > > This patch moves the detaching of sockets from hci_device into workqueue, > so that lock_sock() can be used safely. This requires movement of > deallocation of hci_dev - deallocating device just after > hci_unregister_dev() would be too soon, as it could happen before the > workqueue has been run.
I saw the report on LKML, but I am not really comfortable with this approach. It feels like an ugly hack. This needs more thinking and I think that simplifying the looking between HCI and L2CAP should be the goal.
Regards
Marcel
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