From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757560AbbCPOkd (ORCPT ); Mon, 16 Mar 2015 10:40:33 -0400 Received: from mail-qg0-f42.google.com ([209.85.192.42]:33545 "EHLO mail-qg0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932939AbbCPOkJ (ORCPT ); Mon, 16 Mar 2015 10:40:09 -0400 MIME-Version: 1.0 In-Reply-To: <5506E8D2.60207@dell.com> References: <1424310180-2512-1-git-send-email-mario_limonciello@dell.com> <201502202141.16017@pali> <54EE1917.4020805@dell.com> <201502252145.22577@pali> <5506E8D2.60207@dell.com> Date: Mon, 16 Mar 2015 10:40:07 -0400 Message-ID: Subject: Re: [PATCH] Add a quirk for the Dell XPS 13 (2015) when in PS/2 mode. From: Benjamin Tissoires To: Mario Limonciello , Matthew Garrett Cc: =?UTF-8?Q?Pali_Roh=C3=A1r?= , Jason Ekstrand , Dmitry Torokhov , LKML , "linux-input@vger.kernel.org" , Rob Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 16, 2015 at 10:29 AM, Mario Limonciello wrote: > > On 03/14/2015 02:17 PM, Benjamin Tissoires wrote: >> >> [top posting, sorry] >> >> Jason made some interesting progress today: >> with the patch in https://lkml.org/lkml/2015/3/12/149, the sound card >> is not switched in the I2S mode and works while the touchpad keeps >> using I2C. >> It looks like suspend/resume is also fixed by that :) >> >> I thought it was worth mentioning to the people in this thread. >> >> Cheers, >> Benjamin > > Benjamin, > > Thanks for reporting the progress to me. > > Jason, > > Are you sure upon the particulars of what's happening here? That patch only > modifies the behavior of how the EC is configured. > I'm not aware of any suspend/resume issues, especially related to the EC, so > that really surprises me. My initial suspicion is a suspend/resume issue > you encountered was rare enough that you just haven't hit it yet even with > that patch applied. Maybe something in the out of kernel Broadcom wireless > driver if you are still using the Broadcom card with it. > > I believe you are incorrect in the audio being put in HDA mode. It's more > likely that it's operating closer to properly in I2S mode. Here's some > background around what that patch is doing. Regarding the I2S/HDA problem, I guess I must have interpreted too much what Jason said. All he said was that the patch made his sound card working. [Adding Matthew to the thread, I am sure he will find it interesting] Cheers, Benjamin > When this platform started development the Linux kernel didn't yet respond > true to Windows 2013. All our validation for Linux happened on kernel 3.13. > > _OSI of Windows 2009 is supposed to set it for PS2 mouse, HDA device in ACPI > and configure the EC to set up the Realtek codec for HDA mode. Linux was > planned to mirror this behavior during development. > _OSI of Windows 2013 is supposed to set it up for I2C mouse, I2S audio in > ACPI and configure the EC to set up the Realtek codec for I2S mode. > > From when the platform was in development a _REV check was put in for > Windows 2013 to make sure that in case the kernel started to respond to > Windows 2013 we would still have it running in the intended modes for Linux. > There was a mistake in this _REV check though that caused the I2S ACPI > device but to misconfigure the EC. The reason _REV = 2 and _OSI = Windows > 2013 you are getting working audio is the rt286 driver is starting to be > used. You can validate this by looking at dmesg for lines about rt286. > Realtek recently submitted some patches for this at Dell's request. There > are still a variety of issues with the I2S driver including jack detection > and some other microphone issues. Pulseaudio will possibly need some > patches to work properly with this device too. Ideally we don't want > customers to use I2S mode on Linux until it's solid. > > I don't believe this was in Linus' tree yet, so if you don't have it you can > apply it and it should fix at least one microphone issue when in I2S mode. > http://mailman.alsa-project.org/pipermail/alsa-devel/2015-March/088724.html > > Whether or not that _REV patch gets applied to the kernel we are fixing this > incorrect behavior for Windows 2013 _OSI and Linux in upcoming BIOS A02. > In BIOS A02 there will still be a _REV check but it will do this: > Windows 2013 _OSI, _REV 5: I2C mouse, HDA device in ACPI, configure EC for > HDA mode. > Windows 2013 _OSI, _REV 2: I2C mouse, I2S device in ACPI, configure EC for > I2S mode. > > >