Return-Path: MIME-Version: 1.0 In-Reply-To: <20100606085624.GA393@jh-x301> References: <20100606085624.GA393@jh-x301> Date: Sun, 6 Jun 2010 19:36:46 +0530 Message-ID: Subject: Re: Inquiry Result with repeated set of MAC addresses - Is it a problem with Bluetooth device ? From: Saurabh Thukral To: linux-bluetooth@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Saurabh Wrote: >> The observation is that suppose a device(Nokia N73) with MAC address >> M1 is discoverable, the response to Inquiry Request command is often a >> set of multiple Inquiry Result each with the same MAC address M1. >> >> I had expected that only one Inquiry result with MAC address M1 should >> have been returned. But here what we find is that multiple such >> results with the same MAC address are returned. >> Johan Wrote: > > It's most likely neither, but simply as it's intended to be. I presume > the inquiry results contain the RSSI which will most likely be different > in each event. The purpose of the multiple events is to give you updates > if the signal strength to the device changes. This behaviour is observed on HP Elitebook using broadcom bluetooth adaptor. However when I run the same test on Compaq 510 laptop having the same adaptor, only a single Inquiry result is returned and then inquiry completes. Please note that this is irrespective of whether there is standard inquiry or Inquiry with RSSI. I think having multiple inquiry results all having same MAC address is wrong for following 2 reasons: 1) The procedure of discovery of devices becomes longer 2) I programmed getting inquiry result by sending hci_send_cmd and then polling on hci socket fd for all the events. Since I would be getting multiple events all having result for the same MAC address, this creates a burden to weed out all duplicate entries and return one entry containing MAC address only. I think this way is wrong. -- Regards, Saurabh Thukral