Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932369Ab0DPTyO (ORCPT ); Fri, 16 Apr 2010 15:54:14 -0400 Received: from mail-pv0-f174.google.com ([74.125.83.174]:55172 "EHLO mail-pv0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932222Ab0DPTyN (ORCPT ); Fri, 16 Apr 2010 15:54:13 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:from:date:message-id:subject:to:cc:content-type; b=YznAL44bp2DmrQ/aUNovhFkWj/ENS60yuiYVK1j8wShKdNodDTHicIz0T0wVvA/uSS KGICK9mZu+s5Ku4JSCNQyetLs8d25hhOhO9cdZAev+FqKPcgu2VD5Vr7hJvoRZiORdj7 CnlZ15GIPFGUkchukgKM5Q+xSilP0w2Gjx7hQ= MIME-Version: 1.0 From: "Luis R. Rodriguez" Date: Fri, 16 Apr 2010 12:53:52 -0700 Message-ID: Subject: Power consumption on 802.11 / ASPM / device measurements To: linux-wireless Cc: linux-kernel@vger.kernel.org, yanmin.zhang@intel.com, shaohua.li@intel.com, Sameer Nanda , Jonathan May , David Quan Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1874 Lines: 38 We've been accumulating a few power consumption related documents on the wireless wiki for a while now. One which I saw was missing was for actual power consumption and review of new PCI-E features which should be taken into consideration when debugging power consumption or reviewing it. ASPM is something that I can say I found little to no documentation for when looking into it so I've done a brain dump of what I recall from it, the code review of it, and some e-mail exchanges I've had with Jonathan May @ Atheros. I've stashed together all the power consumption docs at: http://wireless.kernel.org/en/users/Documentation/Power-consumption You'll see there some ASPM docs now and some ath9k specific power consumption metrics/ASPM details. Please review and enhance as you see fit. Yanmin, Shaohua, I see CONFIG_PCIEASPM still marked as experimental, I'm curious if this is still really that experimental and if there are plans for it go out of experimental. Also I am little puzzled with some of the aspm.c code, I see we fill the pci device struct with capability stuff via pcie_aspm_cap_init() but I also see ASPM capability stuff exposed on kernels without CONFIG_PCIEASPM (albeit I see it always disabled on my system at home), so are we filling the capability elsewhere? I think there are some boxes without this kernel config enabled and where ASPM capability info is exposed and does show up as enabled, could be wrong. Also curious -- how often are BIOSes buggy enough for ASPM to get disabled by mistake on the modern devices? And for systems that have no Bios (*cough* ChromeOS) how is this handled? Luis -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/