Subject: Re: [PATCH v7 3/3] nl80211/mac80211: Report signal average
From: Peter Zijlstra <peterz@infradead.org>
To: Bruno Randolf <br1@einfach.org>
Cc: Bob Copeland <me@bobcopeland.com>,
	Johannes Berg <johannes@sipsolutions.net>,
	Jouni Malinen <j@w1.fi>, linville@tuxdriver.com,
	randy.dunlap@oracle.com, blp@cs.stanford.edu,
	linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org,
	Lars_Ericsson@telia.com, stefanr@s5r6.in-berlin.de,
	kosaki.motohiro@jp.fujitsu.com, akpm@linux-foundation.org,
	kevin.granade@gmail.com
In-Reply-To: <201011191807.06013.br1@einfach.org>
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Date: Fri, 19 Nov 2010 13:16:51 +0100
Message-ID: <1290169011.2109.1571.camel@laptop>
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Sender: linux-wireless-owner@vger.kernel.org

On Fri, 2010-11-19 at 18:07 +0900, Bruno Randolf wrote:

> Hmm, maybe I suck in mathemathics, but I don't see a way to do that given the 
> formula:
> 
> (((internal * (weight - 1)) + (val * factor)) / weight

If you assume weight == 2^n, you can write that as:

(((internal << n) - internal) + (val * factor)) >> n