From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Wilson Subject: Re: [PATCH 18/43] drm/i915: fix swizzle detection for gen3 Date: Sun, 29 Jan 2012 17:36:04 +0000 Message-ID: References: <1323867460-5486-1-git-send-email-daniel.vetter@ffwll.ch> <1323867460-5486-18-git-send-email-daniel.vetter@ffwll.ch> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0898338379==" Return-path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTP id AEF209E7AE for ; Sun, 29 Jan 2012 09:36:19 -0800 (PST) In-Reply-To: <1323867460-5486-18-git-send-email-daniel.vetter@ffwll.ch> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: Keith Packard Cc: Daniel Vetter , intel-gfx , stable@kernel.org List-Id: intel-gfx@lists.freedesktop.org --===============0898338379== Content-Type: text/plain On Wed, 14 Dec 2011 13:57:15 +0100, Daniel Vetter wrote: > It looks like the desktop variants of i915 and i945 also have the DCC > register to control dram channel interleave and cpu side bit6 > swizzling. > > Unfortunately internal Cspec/ConfigDB documentation for these ancient chips > have already been dropped and there seem to be no archives. Also > somebody thought the swizzling behaviour is surely a worthy secret to > keep and redacted any mention of these fields from the published Intel > datasheets. > > I suspect the hw engineers were really proud of the page coloring > they've achieved in their first dual channel dram controller with > bit17 - after all Bspec explains in great length the optimal layout of > page frame numbers modulo 4 for the color and depth buffers, too. > Later on when they've started to work on VT-d they shamefully > discoverd their stupidity and tried to cover the tracks ... > > Tested-by: Daniel Vetter (i915g) > Tested-by: Pavel Ondračka (i945g) > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=42625 > Cc: stable@kernel.org > Signed-Off-by: Daniel Vetter It doesn't appear to have broken any of my machines, but I'm going to qualify that to only the laptops I've look at the output of as well as having run i-g-t! Tested-by: Chris Wilson (no changes on 855gm, pnv, gm45, ilk, snb) -Chris -- Chris Wilson, Intel Open Source Technology Centre --===============0898338379== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx --===============0898338379==--