Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751716AbaGGWPe (ORCPT ); Mon, 7 Jul 2014 18:15:34 -0400 Received: from cantor2.suse.de ([195.135.220.15]:40464 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750976AbaGGWPd (ORCPT ); Mon, 7 Jul 2014 18:15:33 -0400 Date: Tue, 8 Jul 2014 00:15:31 +0200 (CEST) From: Jiri Kosina To: Chris Wilson cc: Thomas Meyer , "intel-gfx@lists.freedesktop.org" , Linux Kernel Mailing List , Pavel Machek , Linus Torvalds Subject: Re: [Intel-gfx] Linux 3.16-rc2 In-Reply-To: <20140707160402.GA26405@nuc-i3427.alporthouse.com> Message-ID: References: <1403564870.3091.6.camel@localhost.localdomain> <871tuea7nz.fsf@intel.com> <20140624115753.GD17674@nuc-i3427.alporthouse.com> <1403612670.3091.10.camel@localhost.localdomain> <20140624122737.GF17674@nuc-i3427.alporthouse.com> <20140630100220.GA4934@xo-6d-61-c0.localdomain> <20140630100925.GA18836@nuc-i3427.alporthouse.com> <1404317921.3910.3.camel@localhost.localdomain> <20140707151613.GG5821@phenom.ffwll.local> <20140707160402.GA26405@nuc-i3427.alporthouse.com> User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 7 Jul 2014, Chris Wilson wrote: > > > this patch on top of v3.16-rc3-62-gd92a333 makes the resume from ram > > > regression go away on my machine: > > > > Hm, we could conditionalize this hack on IS_G4X ... Chris, thoughts? > > As different machines favour different w/a, I think the issue is mostly > timing related. It could be sequence of register writes, but we tried > different orders early on. The next experiment I guess would be to > insert small delays between each write to see if that helps. Or to write > each register twice. I actually tried to introduce rather large delays between individual I915_WRITE() calls in the ring initialization sequence a couple weeks ago already, but it resulted in complete machine lockup (which is worse than my usual symptoms) during resume. Therefore I probably lack the knowledge of internal workings of the HW that would allow me to guess what the reasonable timeout value should be. Willing to test any patches. -- Jiri Kosina SUSE Labs -- 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/