Return-path: Received: from s72.web-hosting.com ([198.187.29.21]:55402 "EHLO s72.web-hosting.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933152Ab3BSSbW (ORCPT ); Tue, 19 Feb 2013 13:31:22 -0500 From: Sujith Manoharan MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Message-ID: <20771.50338.434076.484711@gargle.gargle.HOWL> (sfid-20130219_193126_375628_72143122) Date: Tue, 19 Feb 2013 23:59:54 +0530 To: Adrian Chadd Cc: Georgiewskiy Yuriy , Simon Wunderlich , devel@lists.open80211s.org, ath9k-devel@lists.ath9k.org, linux-wireless@vger.kernel.org Subject: Re: [ath9k-devel] improve operational ANI in Mesh mode In-Reply-To: References: <20130219134028.GA26332@pandem0nium> Sender: linux-wireless-owner@vger.kernel.org List-ID: Adrian Chadd wrote: > What's _supposed_ to happen on channel change is this: > > * There's supposed to be an initial set of calibrations done, including NF; > * the time-adjusted noise floor history for that channel is written out; > * The last set ANI parameters for that channel are written out. > > The theory being that the NF and ANI results for a channel are channel > specific and not global. > > _However_ this may or may not be correct or working correctly. ANI > doesn't run for long enough during a channel scan to properly figure > out channel conditions. But on a very noisy channel, you may need some > specifically detuned parameters in order to receive successfully. I think there are bugs in the NF calibration code in ath9k. I see wild fluctuations in the signal level before and after nfcal happens, and this happens in all the chips I tested - AR9285, AR9485, AR9565. Since nfcal is triggered as part of the ANI calibration routine, this would cause issues. Sujith