Return-path: Received: from mail.neratec.com ([46.140.151.2]:49330 "EHLO mail.neratec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751346AbaAQHeC (ORCPT ); Fri, 17 Jan 2014 02:34:02 -0500 Message-ID: <52D8DC0E.40207@neratec.com> (sfid-20140117_083407_539620_98608653) Date: Fri, 17 Jan 2014 08:30:22 +0100 From: Wojciech Dubowik MIME-Version: 1.0 To: Sujith Manoharan CC: ath9k-devel@lists.ath9k.org, linux-wireless@vger.kernel.org Subject: Re: [PATCH 5/5] ath9k: Fix TX IQ calibration for SoC chips References: <1384665016-12022-1-git-send-email-sujith@msujith.org> <1384665016-12022-5-git-send-email-sujith@msujith.org> <52CE934D.1020400@neratec.com> <21198.40916.260973.48444@gargle.gargle.HOWL> <52CEA5A3.2040308@neratec.com> <21198.43395.235654.597422@gargle.gargle.HOWL> <52CEAB24.5090700@neratec.com> <52D3F962.1010302@neratec.com> <21204.319.492595.58625@gargle.gargle.HOWL> <52D402C3.3070606@neratec.com> <21204.1991.201080.986559@gargle.gargle.HOWL> <21204.2384.710460.402183@gargle.gargle.HOWL> <21204.3832.404821.109119@gargle.gargle.HOWL> <52D63EBB.7020607@neratec.com> <21206.17284.157496.206327@gargle.gargle.HOWL> <52D6472B.2060207@neratec.com> <21207.48441.292580.481850@gargle.gargle.HOWL> <21207.49245.151249.759167@gargle.gargle.HOWL> <52D7C62F.2030307@neratec.com> <21208.20686.79159.966434@gargle.gargle.HOWL> In-Reply-To: <21208.20686.79159.966434@gargle.gargle.HOWL> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 01/16/2014 10:36 PM, Sujith Manoharan wrote: > Wojciech Dubowik wrote: >> I guess I won't be able to reproduce bad scan results with wireless >> testing since I have >> changed scan reporting to pure rssi in my openwrt compat. >> In normal case you get a sum of rssi and noise floor and it will be >> correct i.e. when >> NF is shifted by 14db so will be rssi. >> So it's just my use case. >> >> Anyway I have just solved the issue by applying calibrated noise floor >> values from eeprom >> instead of nominal in nf_get functions and nf histogram. Now the rssi >> seems stable in my test >> environment. I have just started testing but it looks promising. > I don't see how that would fix the issue. The race still remains since > there is a window between NF cal init and completion. The results > of the calibration depends on the environment and using default values > from the eeprom will not fix this, I think. > > Sujith I agree it's more of a workaround because there can be situations where measured value is far from calibrated. In my setup it helps but I haven't yet tested what happens in the noisy environment. Do you know a better way to fix this? I am not so deep into calibration tasks but I have a working setup so I could spend more time on that. Wojtek