Return-Path: Message-ID: <49C18674.80801@gmail.com> Date: Thu, 19 Mar 2009 02:40:36 +0300 From: Ilya Rubtsov MIME-Version: 1.0 To: linux-bluetooth@vger.kernel.org Subject: Re: Set Tmin and Tmax for inquiry? References: <49C10E12.3030708@gmail.com> <49C15CC3.3010409@gmail.com> <463DDAC5-0E5C-4BD4-B167-F7590A01EADC@gmail.com> In-Reply-To: <463DDAC5-0E5C-4BD4-B167-F7590A01EADC@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Thanks for reply. I have talk to Vudentz at #blues and now know that both sets of Tmin and Tmax are hardcoded. He also said me that I can use software scheduler, so I do. Also he said that API's interval is longer (min 16, max 24) because there is name resolution feature. So, I wonder - why this feature is not optional? I think not all application need name resolution. Another idea (Vudentz's idea) is to hardcode min 10 to API - if chip is smart it will able to end work earlier. Carles Cufi пишет: > Hi Ilya, > > The hcitool application uses the HCI library function hci_send_req() > to send a periodic inquiry request to the controller. The max and min > periods are hardcoded to 16 and 10 respectively, and there is no user > option to change those. In the case of your python script I can't tell > you for sure because I haven't looked at the code of the python BlueZ > bindings, but if the API call it presents to you has no Tmin and Tmax > that means it's hardcoded there too. The bluetoothd (formerly called > hcid) has absolutely nothing to do with the hcitool since this tool > bypasses it completely. For python, you should look at the code for > the bindings and find out how the API implementation handles your call. > > -- > Carles > > On Mar 18, 2009, at 9:42 PM, Ilya Rubtsov wrote: > >> Oops. Mistake. Right is: 'max 24 min 16 lap 0x9e8b33 len 8 num 0' >> (StartDiscovery) and 'max 16 min 10 lap 0x9e8b33 len 8 num 0' (hcitool) >> >> Ilya Rubtsov пишет: >> >>> Hi >>> >>> I'm developing an application for bluecasting. So period of periodic >>> inquire is important for me. >>> AFAIK, inquire process takes 10.24 seconds (Bluetooth 2.0). But if I >>> use StartDiscovery method in python script, then I see this in hcidump: >>> >>> < HCI Command: Periodic Inquiry Mode (0x01|0x0003) plen 9 >>> max 24 min 16 lap 0x9e8b33 len 8 num 0 >>> >>> and I get "Inquiry Complete" event every ~24-30 second. But if I use >>> 'hcitool spinq', then I see: >>> >>> < HCI Command: Periodic Inquiry Mode (0x01|0x0003) plen 9 >>> max 24 min 16 lap 0x9e8b33 len 8 num 0 >>> >>> and "Inquiry Complete" event takes place every ~13-15 seconds. And >>> in both cases all remote devices is being founded, so I don't see >>> any reason for longer inquiring. AFAIK HCID internally sets Tmin and >>> Tmax parameters, but is there any way to affect to its 'decision'? >>> >>> P.S. Excuse me for my English :( >> >> -- >> To unsubscribe from this list: send the line "unsubscribe >> linux-bluetooth" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >