Return-Path: Date: Tue, 16 Nov 2010 10:56:47 +0200 From: Ville Tervo To: ext Mike Tsai Cc: "linux-bluetooth@vger.kernel.org" Subject: Re: [RFC] Interface to set LE connection parameters Message-ID: <20101116085647.GG16464@null> References: <20101115120632.GB16464@null> <35B17FE5076C7040809188FBE7913F98406D465470@SC1EXMB-MBCL.global.atheros.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <35B17FE5076C7040809188FBE7913F98406D465470@SC1EXMB-MBCL.global.atheros.com> Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Mike, n Mon, Nov 15, 2010 at 07:15:44PM +0100, ext Mike Tsai wrote: > Hi Ville, > > -----Original Message----- > From: linux-bluetooth-owner@vger.kernel.org [mailto:linux-bluetooth-owner@vger.kernel.org] On Behalf Of Ville Tervo > Sent: Monday, November 15, 2010 4:07 AM > To: linux-bluetooth@vger.kernel.org > Subject: [RFC] Interface to set LE connection parameters > > Hi, > > LE profiles have different requirements for connection parameters. Mainly > trying to balance between power consumption and latencies. Probably more will > factors will be in future. > > Currently I have plan to introduce new l2cap socket option which can be used > before connection creation to set inital settings and also change settings > while having a connection. > > Since there is no equivalents in EDR/BR connection I'm planning to make then > apply only LE connection. > > > Other question which parameters should be exposed to user space? Connection > creation and connection update have these common parameters. Connection > creation has in addition some other parameters also but they should be handled > in some other way. > > __le16 conn_interval_min; > __le16 conn_interval_max; > __le16 conn_latency; > __le16 supervision_timeout; > __le16 min_ce_len; > __le16 max_ce_len; > > So far I have had two ideas. The first is to simply expose all these fields > with sock_opt. In that way profiles would be able to define their requirements > also in future without any sock opt changes. > > Second is to define BT_LE_LOW_LAT for low latency connection requirements and > BT_LE_LOW_POWER connection where the latency is not an issue. It would make > usage of this sock opt interface simplier. OTOH the only user should be > bluetoothd so it doesn't need to be as simple as possible. > > > Comments please. > > [MTsai] - how about following parameters, > > Scan internal, > Scan window, > Peer address type, These are connection creation parameters. Maybe BT_LE_LOW_LAT/BT_LE_LOW_POWER could be used also for these values. But I think they should defined in some other way. -- Ville