Hi Dave,
There's logic in __rfcomm_dlc_close:
rfcomm_dlc_lock(d);
d->state = BT_CLOSED;
d->state_changed(d, err);
rfcomm_dlc_unlock(d);
In rfcomm_dev_state_change, it's possible that rfcomm_dev_put try to
take the
dlc lock, then we will deadlock.
Here fixed it by unlock dlc before rfcomm_dev_get in
rfcomm_dev_state_change.
why not unlock just before rfcomm_dev_put? it's because there's
another problem.
rfcomm_dev_get/rfcomm_dev_del will take rfcomm_dev_lock, but in
rfcomm_dev_add
the lock order is : rfcomm_dev_lock --> dlc lock
so I unlock dlc before the taken of rfcomm_dev_lock.
Actually it's a regression caused by commit
1905f6c736cb618e07eca0c96e60e3c024023428, the dlc state_change could
be two
callbacks : rfcomm_sk_state_change and rfcomm_dev_state_change. I
missed the rfcomm_sk_state_change that time.
Thanks Arjan van de Ven <arjan@xxxxxxxxxxxxxxx> for the effort in
commit
4c8411f8c115def968820a4df6658ccfd55d7f1a
but he missed the rfcomm_dev_state_change lock issue.
Signed-off-by: Dave Young <hidave.darkstar@xxxxxxxxx>
looks good. Thanks for adding a clear comment why we have to do it
this way.
Acked-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Regards
Marcel
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