Return-Path: MIME-Version: 1.0 In-Reply-To: <1324417223.1965.137.camel@aeonflux> References: <1324417223.1965.137.camel@aeonflux> Date: Thu, 22 Dec 2011 19:39:13 +0530 Message-ID: Subject: Re: [RFC BlueZ]Proximity Monitor Discussion From: Hemant Gupta To: Marcel Holtmann Cc: Claudio Takahasi , Anderson Briglia , Anderson Lizardo , linux-bluetooth@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Thanks Marcel for the clarifications. On Wed, Dec 21, 2011 at 3:10 AM, Marcel Holtmann wrote: > Hi Hemant, > >> > Please sync with Anderson Briglia, he already sent a RFC to the ML >> > some months ago. >> > In the Bluetooth Summit(Prague), we decided to not proceed with RSSI >> > monitor emulation in the kernel until we have a clear idea or spec >> > defining how the controllers will implement RSSI monitoring. >> Could you please provide some details about what was discussed in the summit. >> >> > The ideia was to provide transparency, the userspace doesn't need to >> > know if RSSI monitoring is emulated or not. >> >> As per my understanding the BT spec (4.0, Volume 2, Part E, Section >> 7.5.4) the HCI_Read_RSSI command can be used to retrieve the RSSI from >> the controller. In our case, I have tested it against ST-Ericsson BT >> controller ?and it works in our case. Are you suggesting that until we >> know how the RSSI is determined in controller, we should not implement >> this functionality in kernel ? I ask this because in Proximity Spec, >> it is mentioned that the monitor should use appropriate calculations >> to prevent false alerts on reporter, so if we leave this to layer >> above BlueZ to do this part, then we are pretty independent with the >> approach of implementation of Path Loss RSSI Monitoring in BlueZ and >> Kernel. >> >> If I misunderstood anything please clarify. > > we need proper notifications about RSSI changes triggered by the > Bluetooth controller and not having the host polling the controller all > the time. So just the existence of HCI_Read_RSSI is not enough to make > this part efficient. And we can only emulate the RSSI notification via > polling once we know how the new HCI commands will look like. We are > kinda stuck here. > > Regards > > Marcel > > -- Best Regards Hemant Gupta ST-Ericsson India