From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adam Jackson Subject: [PATCH 0/5] Initial DisplayPort OUI probing Date: Mon, 14 May 2012 16:05:44 -0400 Message-ID: <1337025949-2355-1-git-send-email-ajax@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" 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 9DEC79E938 for ; Mon, 14 May 2012 13:05:53 -0700 (PDT) Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q4EK5qZS017132 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 14 May 2012 16:05:52 -0400 Received: from ihatethathostname.lab.bos.redhat.com (ihatethathostname.lab.bos.redhat.com [10.16.43.238]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id q4EK5qVk017041 for ; Mon, 14 May 2012 16:05:52 -0400 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org Errors-To: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org To: dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org DisplayPort has an escape hatch by which devices can identify each other. I'm not super thrilled that it does, since that's just a clever way of getting the spec to explicitly bless interoperability bugs. But it may be useful information when debugging link training problems, and there's a cute trick you can do on iMacs that I think will require knowing this information, so we may as well fill it in. Tested on a Lenovo T500 against a DP->VGA adaptor (which turns out to be an ST Microelectronics chip, who knew) and an HP LP2480zx (which does not advertise OUI support, but also harmlessly returns 0s for the OUI registers if you read them anyway). - ajax