Return-path: Received: from mail-pw0-f46.google.com ([209.85.160.46]:50646 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752458Ab0GZWnY (ORCPT ); Mon, 26 Jul 2010 18:43:24 -0400 MIME-Version: 1.0 In-Reply-To: <20100726223326.GA6904@srcf.ucam.org> References: <20100726201322.GI14855@tux> <1280177362.3721.7.camel@maxim-laptop> <20100726210651.GJ14855@tux> <1280179033.3721.15.camel@maxim-laptop> <20100726212543.GA5424@srcf.ucam.org> <20100726222113.GA6487@srcf.ucam.org> <20100726222909.GA6773@srcf.ucam.org> <20100726223326.GA6904@srcf.ucam.org> From: "Luis R. Rodriguez" Date: Mon, 26 Jul 2010 15:43:04 -0700 Message-ID: Subject: Re: [ath5k-devel] [PATCH v3] ath5k: disable ASPM To: Matthew Garrett Cc: Maxim Levitsky , "ath5k-devel@lists.ath5k.org" , "linux-wireless@vger.kernel.org" , David Quan , "Luis R. Rodriguez" , linux-kernel , "kernel-team@lists.ubuntu.com" , Luis Rodriguez , Jussi Kivilinna , "tim.gardner@canonical.com" Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Mon, Jul 26, 2010 at 3:33 PM, Matthew Garrett wrote: > On Mon, Jul 26, 2010 at 03:31:28PM -0700, Luis R. Rodriguez wrote: >> On Mon, Jul 26, 2010 at 3:29 PM, Matthew Garrett wrote: >> > On Mon, Jul 26, 2010 at 03:26:37PM -0700, Luis R. Rodriguez wrote: >> > >> >> What I meant was that the PCI config space would already have L1 >> >> enabled if L1 worked, so I don't see why we would need to nitpick out >> >> specifics here. All Atheros PCIE chips should work with L1. The advise >> >> given is to disable L0s though. I believe AR2425 would be one which >> >> likely had L0s enabled but requires it to be disabled. Not sure of >> >> others. But this is why I am saying this can be done globally for all >> >> ath5k chipsets. >> > >> > If L1 is set but the chip is pre-PCIe 1.1 then we'll disable L1 unless >> > the driver tells us that it's functional. The .inf from the Windows >> > driver seemed to suggest that only a subset of the chips re-enabled L1 >> > there, but if it's ok in general then that's a straightforward one-line >> > patch. >> >> But why can't we just rely on what the device already has on its PCI >> config space and only ensure to disable L0s? > > Because we globally disable ASPM on pre-1.1 devices, because that's what > Windows does. It makes it easier for us to figure out what level of > support we can expect from different hardware revisions. I see.. thanks Mathew... in that case since L1 works on all devices we could just force enable L1 for all PCIE devices. What do you think? Luis