Return-Path: Date: Thu, 24 May 2012 10:51:12 +0300 From: Andrei Emeltchenko To: Mat Martineau Cc: linux-bluetooth@vger.kernel.org, pkrystad@codeaurora.org Subject: Re: [PATCHv1 01/17] Bluetooth: A2MP: Create A2MP channel Message-ID: <20120524075105.GB24715@aemeltch-MOBL1> References: <1337351150-20526-1-git-send-email-Andrei.Emeltchenko.news@gmail.com> <1337351150-20526-2-git-send-email-Andrei.Emeltchenko.news@gmail.com> <20120523074950.GA32022@aemeltch-MOBL1> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Mat, On Wed, May 23, 2012 at 08:44:22AM -0700, Mat Martineau wrote: > >>>+static struct l2cap_chan *a2mp_chan_open(struct l2cap_conn *conn) > >>>+{ > >>>+ struct l2cap_chan *chan; > >>>+ > >>>+ chan = l2cap_chan_create(); > >>>+ if (!chan) > >>>+ return NULL; > >>>+ > >>>+ BT_DBG("chan %p", chan); > >>>+ > >>>+ hci_conn_hold(conn->hcon); > >> > >>Holding the hcon will keep the ACL open after all of the other L2CAP > >>channels have closed (unless I missed some code later in the patch > >>series). The A2MP fixed channel should not keep the ACL open. If > >>the connection is not held here, then there shouldn't be a put in > >>l2cap_chan_del for the A2MP channel either. > > > >l2cap_chan_del makes hci_conn_put, also for a2mp channel. The behavior is > >the same for fixed and normal channels. > > And when does l2cap_chan_del get called for a fixed channel? The > fixed channel must not do an hci_conn_hold so the ACL is allowed to > close when all dynamic L2CAP channels have closed. The current approach is to have amp_mgr for hci_conn. It will be freed when in hci_conn_del together with other l2cap channels in hci_chan_list_flush and then we make amp_mgr_put() and destroy mgr. The idea is to make a2mp chan similar to other chans and other chans do hci_conn_hold and hci_conn_put. Otherwise I would need to add extra checks before hci_conn_put which is ugly. I've tested this with PTS and no memory leaks found so far. Best regards Andrei Emeltchenko