From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-gx0-f174.google.com ([209.85.161.174]:44509 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754743Ab0G1VVf (ORCPT ); Wed, 28 Jul 2010 17:21:35 -0400 Received: by gxk23 with SMTP id 23so1893845gxk.19 for ; Wed, 28 Jul 2010 14:21:34 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <4C509CE1.90503@openwrt.org> References: <1280339151-37084-1-git-send-email-nbd@openwrt.org> <1280339151-37084-2-git-send-email-nbd@openwrt.org> <4C509CE1.90503@openwrt.org> From: "Luis R. Rodriguez" Date: Wed, 28 Jul 2010 14:21:14 -0700 Message-ID: Subject: Re: [PATCH 2/3] ath9k_hw: clean up per-channel calibration data To: Felix Fietkau Cc: linux-wireless@vger.kernel.org, linville@tuxdriver.com, Jouni Malinen Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wed, Jul 28, 2010 at 2:10 PM, Felix Fietkau wrote: > On 2010-07-28 10:52 PM, Luis R. Rodriguez wrote: >> On Wed, Jul 28, 2010 at 10:45 AM, Felix Fietkau wrote: >>> The noise floor history buffer is currently not kept per channel, which >>> can lead to problems when changing channels from a clean channel to a >>> noisy one. Also when switching from HT20 to HT40, the noise floor >>> history buffer is full of measurements, but none of them contain data >>> for the extension channel, which it needs quite a bit of time to recover >>> from. >>> >>> This patch puts all the per-channel calibration data into a single data >>> structure, and gives the the driver control over whether that is used >>> per-channel or even not used for some channels. >>> >>> For ath9k_htc, I decided to keep this per-channel in order to avoid >>> creating regressions. >>> >>> For ath9k, the data is kept only for the operating channel, which saves >>> some space. ath9k_hw takes care of wiping old data when the operating >>> channel or its channel flags change. >>> >>> Signed-off-by: Felix Fietkau >> >> But this also means every time we want to get operational on a channel >> we have to learn the current noise all over again. This means for WiFi >> Direct every channel swap we'd have to learn to walk, which happens >> quite often. What do you think? Sorry, I know we discussed this >> approach and I seemed fine but this just occurred to me now, and will >> become really important later when we support WiFi Direct. > When we get to implementing per-vif channel settings with switching > being done in mac80211, we can just move the calibration data to ath9k's > virtual interface data and thus keep the calibration for multiple > operating channels. Sounds good. This would currently break the ath9k virtual wiphy's calibration stuff :P (not like I care), Jouni? Luis