Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933056Ab1BYXFs (ORCPT ); Fri, 25 Feb 2011 18:05:48 -0500 Received: from cable-static-49-187.intergga.ch ([157.161.49.187]:58850 "EHLO mail.ffwll.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932869Ab1BYXFr (ORCPT ); Fri, 25 Feb 2011 18:05:47 -0500 X-Spam-ASN: X-Spam-Spammy: 0.965-+--H*r:mail.ffwll.ch, 0.895-+--wish, 0.874-+--H*F:D*ffwll.ch X-Spam-Hammy: 0.000-+--HCc:D*freedesktop.org, 0.000-+--HCc:D*lists.freedesktop.org, 0.000-+--HCc:U*intel-gfx Date: Sat, 26 Feb 2011 00:05:27 +0100 From: Daniel Vetter To: Chris Wilson Cc: Jan Niehusmann , intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [Intel-gfx] [PATCH] intel-gtt: fix memory corruption with GM965 and >4GB RAM Message-ID: <20110225230527.GC3601@viiv.ffwll.ch> Mail-Followup-To: Chris Wilson , Jan Niehusmann , intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org References: <20110223233022.GA3439@x61s.reliablesolutions.de> <20110225123056.GA3759@x61s.reliablesolutions.de> <20110225211646.GA6837@x61s.reliablesolutions.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Operating-System: Linux viiv 2.6.38-rc5-00035-g3077686 User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1063 Lines: 23 On Fri, Feb 25, 2011 at 10:18:16PM +0000, Chris Wilson wrote: > So, I'm happy to use your patch to workaround the known erratum. I just > wish I had an explanation as to what is actually causing the corruption. > What I want to make sure is that we don't paper over a real bug by > thinking it is yet another silicon issue. Actually, on style points I prefer your patch: The hw status page is allocated with drm_pci_alloc which calls dma_alloc_coherent, so setting the coherent mask is sufficient. The dma mask set in the gtt is essentially useless, because we call get_user_pages on everything anyway (in gem - iirc agp uses it). I just think it's confusing to limit the general dma mask and continue to happily map pages above 4G. Cheers, Daniel -- Daniel Vetter Mail: daniel@ffwll.ch Mobile: +41 (0)79 365 57 48 -- 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/