From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12984C43381 for ; Thu, 7 Mar 2019 10:49:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D7DBE20684 for ; Thu, 7 Mar 2019 10:49:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726410AbfCGKtd (ORCPT ); Thu, 7 Mar 2019 05:49:33 -0500 Received: from imap1.codethink.co.uk ([176.9.8.82]:60330 "EHLO imap1.codethink.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726252AbfCGKtc (ORCPT ); Thu, 7 Mar 2019 05:49:32 -0500 Received: from [167.98.27.226] (helo=[10.35.4.91]) by imap1.codethink.co.uk with esmtpsa (Exim 4.84_2 #1 (Debian)) id 1h1qaf-0003mR-Q8; Thu, 07 Mar 2019 10:49:29 +0000 Subject: Re: [PATCH] drm/i915/ddi: Fix default eDP detection on port A To: Jani Nikula , joonas.lahtinen@linux.intel.com, rodrigo.vivi@intel.com, airlied@linux.ie, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org References: <20190306200618.17405-1-thomas.preston@codethink.co.uk> <874l8fm72f.fsf@intel.com> <87va0vkm6e.fsf@intel.com> From: Thomas Preston Message-ID: <1bc46e12-5cee-e3d0-83db-2feee4fe5210@codethink.co.uk> Date: Thu, 7 Mar 2019 10:49:29 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <87va0vkm6e.fsf@intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/03/2019 10:34, Jani Nikula wrote: >>> On Wed, 06 Mar 2019, Thomas Preston wrote: >>>> We rely on VBT DDI port info for eDP detection on GEN9 platforms and >>>> above. This breaks GEN9 platforms which don't have VBT because port A >>>> eDP now defaults to false. Fix this by defaulting to true when VBT is >>>> missing. >>> >>> Please include more details about the machine that doesn't have VBT. Why >>> don't you have VBT? >>> >> >> We have upgraded from an earlier kernel version (an Intel BSP on v4.1) >> which did not require VBT and so our BIOS isn't set up correctly. The >> BIOS doesn't set ASLS and fails to find ACPI OpRegion: >> >> [ 9.368433] [drm:intel_opregion_setup [i915]] graphic opregion physical addr: 0x0 >> [ 9.368490] [drm:intel_opregion_setup [i915]] ACPI OpRegion not supported! >> >> So now our port A is DP instead of eDP. I was hoping a return to "default" >> values would remedy this, but I think it's pretty clear now that we should >> focus on fixing VBT. > > In the long run you'll have better control of what your specific product > does by using a VBT. However, I think we'll probably have to take the > patch anyway. > Would you like me to resubmit with the suggested changes? >> I've found a default VBT in the BSP but not sure how to get it into BIOS. >> If you could point me in the right direction here that would be really >> useful! > > There are dangers with default VBTs too. They might contain incorrect > information about the specific board you have. You'll also have to set > up the opregion, not just VBT. > I believe OpRegion is being set up correctly with ACPI tables, but ASLS=0 (points to OpRegion) is quite suspicious. I need to do more digging around how our BIOS is set up. > I'm afraid I can't help you there. You already know where to look to see > how the kernel side expects things to work. > > For testing, the i915.vbt_firmware module parameter is helpful, so you > don't need to change your BIOS to change the VBT. > That's great thanks, I will work on VBT using this for now.