From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adam Jackson Subject: Re: [PATCH] drm/i915: always set FDI composite sync bit Date: Tue, 11 Oct 2011 10:10:24 -0400 Message-ID: <4E944E50.1070903@redhat.com> References: <1318282132-8104-1-git-send-email-jbarnes@virtuousgeek.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by gabe.freedesktop.org (Postfix) with ESMTP id 19A279F783 for ; Tue, 11 Oct 2011 07:10:27 -0700 (PDT) In-Reply-To: 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: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On 10/10/11 7:22 PM, Keith Packard wrote: > On Mon, 10 Oct 2011 14:28:52 -0700, Jesse Barnes wrote: > >> It's needed for 3 pipe support as well as just regular functionality >> (e.g. DisplayPort). > > Any explanation on how you get sync without this? As in, why did this > ever work? To a first approximation, it didn't. I was never able to get anything reliably lit up besides the boot output (and only that one; hotplug after was a disaster). I don't have register dumps handy to compare BIOS setup with this change, but I could if needed. It still seems entirely magical and probably wrong in some situations. And I'm thrilled to see that PPT is functionally different from CPT (seriously, stop doing that) instead of just moving bit definitions around (seriously, stop doing that). But this change is massively better than before. - ajax