Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753544Ab3GPIbz (ORCPT ); Tue, 16 Jul 2013 04:31:55 -0400 Received: from s16502780.onlinehome-server.info ([87.106.93.118]:50596 "EHLO fireflyinternet.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753130Ab3GPIbv (ORCPT ); Tue, 16 Jul 2013 04:31:51 -0400 X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.73.22; Date: Tue, 16 Jul 2013 09:31:40 +0100 From: Chris Wilson To: Konstantin Khlebnikov , David Airlie , intel-gfx , Linux Kernel Mailing List , dri-devel Subject: Re: [PATCH] drm/i915: fix long-standing SNB regression in power consumption after resume Message-ID: <20130716083140.GK2823@cantiga.alporthouse.com> Mail-Followup-To: Chris Wilson , Konstantin Khlebnikov , David Airlie , intel-gfx , Linux Kernel Mailing List , dri-devel References: <20130714163009.22374.22100.stgit@zurg> <51E2E65D.5050803@openvz.org> <20130716063101.GK5784@phenom.ffwll.local> <20130716074458.GM5784@phenom.ffwll.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130716074458.GM5784@phenom.ffwll.local> User-Agent: Mutt/1.5.21 (2010-09-15) X-Originating-IP: 78.156.73.22 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1203 Lines: 24 On Tue, Jul 16, 2013 at 09:44:59AM +0200, Daniel Vetter wrote: > The issue I have with the current patch is that it looks a bit like > duct-tape since the point where we drop the forcewake references seems to > lack justification. The write to MBCTL itself will temporarily wake up the > chip, so just wrapping that up in with forcewake is very likely not good > enough. So I fear that we'll only hold forcewake long enough on most > systems and still have a bunch of oddball broken systems out there. > > Holding forcewake otoh until we've fully set up rps/rc6 makes imo tons of > sense, hence why I've brought up the idea. Same reasoning applies to > extending the w/a to all systems supporting rc6. In which case disable rc6 at the start of init gating and only enable it at the end of the deferred task. That I think will better test your hypothesis and make the transistion steps clearer. -Chris -- Chris Wilson, Intel Open Source Technology Centre -- 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/