From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-ew0-f214.google.com ([209.85.219.214]:59029 "EHLO mail-ew0-f214.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751169AbZGaTfP convert rfc822-to-8bit (ORCPT ); Fri, 31 Jul 2009 15:35:15 -0400 Received: by ewy10 with SMTP id 10so1752289ewy.37 for ; Fri, 31 Jul 2009 12:35:15 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1249067385.20276.16.camel@mj> References: <20090731181020.GE7963@makis> <43e72e890907311115h56df6ac0p1ea7165e305a10ee@mail.gmail.com> <40f31dec0907311125o1654bd23jee861ba8bea57611@mail.gmail.com> <1249067385.20276.16.camel@mj> Date: Fri, 31 Jul 2009 22:35:14 +0300 Message-ID: <40f31dec0907311235g63c10e53obec06ba542d942cd@mail.gmail.com> Subject: Re: [ath5k-devel] [PATCH 4/4] ath5k: Use SWI to trigger calibration From: Nick Kossifidis To: Pavel Roskin Cc: "Luis R. Rodriguez" , jirislaby@gmail.com, linux-wireless@vger.kernel.org, ath5k-devel@lists.ath5k.org, linville@tuxdriver.com Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: 2009/7/31 Pavel Roskin : > On Fri, 2009-07-31 at 21:25 +0300, Nick Kossifidis wrote: > >> a) We don't need a timer for this, there is no need for accuracy >>     even with round_jiffies i think this is a waste of resources. >>     Also we don't need to run calibration if we are idle (no interrupts). > > It doesn't sound right to me. > > Can it be that the device gets so miscalibrated during the silence that > it won't be able to receive signal once it's there?  Say, the device is > set to channel 1 but it actually listens to channel 3, and there are > some weak beacons on channel 1. > Nope calibration deals mostly with noise immunity, it calculates the noise floor and fixes QAM constellation. It's not related to the synthesizer so it's not related to the channel frequency. > And then there is an issue of the frequency straying outside the > permitted spectrum.  Perhaps the transmission will trigger interrupts > and thus recalibration, but in case of scanning, the first probe > requests could be on wrong frequencies. > On each reset we trigger calibration so no worries there. -- GPG ID: 0xD21DB2DB As you read this post global entropy rises. Have Fun ;-) Nick