Return-Path: From: "Ganir, Chen" To: Anderson Lizardo , Marcel Holtmann CC: "anderson.briglia@openbossa.org" , "linux-bluetooth@vger.kernel.org" , Bruna Moreira Date: Thu, 16 Jun 2011 08:03:49 +0200 Subject: RE: [RFC 7/7] Update Management API documentation Message-ID: <7769C83744F2C34A841232EF77AEA20C01D395DC90@dnce01.ent.ti.com> References: <4df91d74.0b73650a.190f.17ad@mx.google.com> <1308175855.2196.7.camel@aeonflux> In-Reply-To: Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 List-ID: > -----Original Message----- > From: linux-bluetooth-owner@vger.kernel.org [mailto:linux-bluetooth- > owner@vger.kernel.org] On Behalf Of Anderson Lizardo > Sent: Thursday, June 16, 2011 2:48 AM > To: Marcel Holtmann > Cc: anderson.briglia@openbossa.org; linux-bluetooth@vger.kernel.org; > Bruna Moreira > Subject: Re: [RFC 7/7] Update Management API documentation >=20 > Hi Marcel, >=20 > On Wed, Jun 15, 2011 at 6:10 PM, Marcel Holtmann > wrote: > > so why are these two separate commands. Just reading them in one > kernel > > call might be a lot better. Including everything else you need to > know > > about the connection. Also TX power can be local and remote TX power > if > > I remember this correctly. >=20 > The issue I see with your proposal is that for Proximity (currently > the only user of this information) we read TX power from server > (reporter) using GATT, while RSSI is read on client (monitor) side. By > reading both, we would need to issue two separate HCI commands (and > wait for both responses), but will always use only one value, > depending on local BlueZ role. >=20 > Also note that on latest Proximity profile drafts, it is mentioned > that the TX power on reporter will never change during a connection, > and thus it should be read only once when the connection is > established. RSSI (which is read "locally" on monitor side), on the > other hand, should be read periodically for path loss calculation. Anderson, Please note that this is currently true for LE connection, but may change=20 in the future. In addition, TX Power for BR/EDR may change during the=20 connection (by the controller, depending on LMP commands), so reading it=20 periodically and updating the GATT server must be implemented. Chen Ganir.