Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753328AbaBSI7O (ORCPT ); Wed, 19 Feb 2014 03:59:14 -0500 Received: from mga09.intel.com ([134.134.136.24]:38080 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751809AbaBSI7M (ORCPT ); Wed, 19 Feb 2014 03:59:12 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,504,1389772800"; d="scan'208";a="457947543" Message-ID: <5304725A.3020909@intel.com> Date: Wed, 19 Feb 2014 16:59:06 +0800 From: Aaron Lu MIME-Version: 1.0 To: Matthew Garrett CC: Daniel Vetter , Chris Wilson , Jani Nikula , "Rafael J. Wysocki" , Oleksij Rempel , "intel-gfx@lists.freedesktop.org" , "linux-kernel@vger.kernel.org" , ACPI Devel Mailing List Subject: Re: [PATCH] drm/i915/opregion: work around buggy firmware that provides 8+ output devices References: <52FAE504.8020001@intel.com> <20140212103156.GC5298@nuc-i3427.alporthouse.com> <52FC8C01.1040002@intel.com> <20140213100814.GM14909@nuc-i3427.alporthouse.com> <53045DD1.5010406@intel.com> <20140219073339.GA30685@srcf.ucam.org> In-Reply-To: <20140219073339.GA30685@srcf.ucam.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/19/2014 03:33 PM, Matthew Garrett wrote: > On Wed, Feb 19, 2014 at 03:31:29PM +0800, Aaron Lu wrote: > >> DID2 is in system memory region and has some assigned value like 0x400 >> when we read it. For this case it is easy since there is only one output >> device that is of type LVDS so we can match it to connector of type eDP >> or LVDS, suppose there is only one such connector. But for output >> devices' whose _ADR has the value of 0x301, 0x302, etc. I have no idea >> how to match them up to the connectors of that type as we can't be sure >> the probe order we have used in i915 driver is the same as BIOS'. > > Non-standard _ADR values are assigend by the GPU vendor, so Intel should > be able to provide you with the correct interpretations. It doesn't seem the _ADR value has to be the format defined by _DOD, as the example of the ACPI spec gives: Method (_ADR, 0) { return(0x0100) } So that is not the problem here. The problem is, we don't have any way of matching an ACPI output device node to a drm connector of the same type when there are more than 1 of those with the same type, i.e. we don't know how the index value are assigned by BIOS. -- 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/