Return-path: Received: from nbd.name ([46.4.11.11]:42305 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751705Ab3EPLth (ORCPT ); Thu, 16 May 2013 07:49:37 -0400 Message-ID: <5194C7CC.1090109@openwrt.org> (sfid-20130516_134942_451088_E08CA437) Date: Thu, 16 May 2013 13:49:32 +0200 From: Felix Fietkau MIME-Version: 1.0 To: Simon Wunderlich CC: linux-wireless@vger.kernel.org, Johannes Berg , Mathias Kretschmer , Simon Wunderlich Subject: Re: [PATCHv3 08/18] cfg80211/mac80211: use reduced txpower for 5 and 10 MHz References: <1368702045-27598-1-git-send-email-siwu@hrz.tu-chemnitz.de> <1368702045-27598-9-git-send-email-siwu@hrz.tu-chemnitz.de> In-Reply-To: <1368702045-27598-9-git-send-email-siwu@hrz.tu-chemnitz.de> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 2013-05-16 1:00 PM, Simon Wunderlich wrote: > Some regulations (like germany, but also FCC) express their transmission > power limit in dBm/MHz or mW/MHz. To cope with that and be on the safe > side, reduce the maximum power to half (10 MHz) or quarter (5 MHz) > when operating on these reduced bandwidth channels. As far as I know, chan->max_power can in some cases contain the hardware limit instead of the regulatory limit. It's safer to check chan->max_reg_power to see if a reduction is necessary. - Felix