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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 A2706CA9EC0 for ; Mon, 28 Oct 2019 16:29:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7E55321783 for ; Mon, 28 Oct 2019 16:29:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391002AbfJ1Q3E (ORCPT ); Mon, 28 Oct 2019 12:29:04 -0400 Received: from mga02.intel.com ([134.134.136.20]:37947 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732565AbfJ1Q3D (ORCPT ); Mon, 28 Oct 2019 12:29:03 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Oct 2019 09:29:02 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,240,1569308400"; d="scan'208";a="211478363" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by orsmga002.jf.intel.com with ESMTP; 28 Oct 2019 09:29:00 -0700 Received: from andy by smile with local (Exim 4.92.2) (envelope-from ) id 1iP7t5-0005D3-EA; Mon, 28 Oct 2019 18:28:59 +0200 Date: Mon, 28 Oct 2019 18:28:59 +0200 From: Andy Shevchenko To: Hans de Goede Cc: Mark Brown , Adrian Hunter , Andrey Zhizhikin , lgirdwood@gmail.com, lee.jones@linaro.org, linux-kernel@vger.kernel.org, Andrey Zhizhikin Subject: Re: [PATCH 0/2] add regulator driver and mfd cell for Intel Cherry Trail Whiskey Cove PMIC Message-ID: <20191028162859.GO32742@smile.fi.intel.com> References: <20191024142939.25920-1-andrey.zhizhikin@leica-geosystems.com> <20191025075335.GC32742@smile.fi.intel.com> <20191025075540.GD32742@smile.fi.intel.com> <166c9855-910d-a70c-ba86-6aebe5f2346d@intel.com> <20191028124554.GF5015@sirena.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 28, 2019 at 02:26:21PM +0100, Hans de Goede wrote: > On 28-10-2019 13:45, Mark Brown wrote: > > On Mon, Oct 28, 2019 at 02:41:46PM +0200, Adrian Hunter wrote: > > > On 25/10/19 10:55 AM, Andy Shevchenko wrote: > > > > > > Since it's about UHS/SD, Cc to Adrian as well. > > > > > My only concern is that the driver might conflict with ACPI methods trying > > > to do the same thing, e.g. there is one ACPI SDHC instance from GPDWin DSDT > > > with code like this: > > Oh, right that is a very good point. > > > That's certainly what's idiomatic for ACPI (though machine specific > > quirks are too!). The safe thing to do would be to only register the > > supply on systems where we know there's no ACPI method. > > Right, so as I mentioned before Andrey told me about the evaluation > board he is using I was aware of only 3 Cherry Trail devices using > the Whiskey Cove PMIC. The GPD win, the GPD pocket and the Lenovo > Yoga book. I've checked the DSDT of all 3 and all 3 of them offer > voltage control through the Intel _DSM method for voltage control. > > I've also actually tested this on the GPD win and 1.8V signalling > works fine there without needing Andrey's patch. > > So it seems that Andrey's patch should only be active on his > dev-board, as actual production hardware ships with the _DSM method. > > I believe that the best solution is for the Whiskey Cove MFD driver: > drivers/mfd/intel_soc_pmic_chtwc.c > > To only register the new cell on Andrey's evaluation board model > (based in a DMI match I guess). Another option would be to do > the DMI check in the regulator driver, but that would mean > udev will needlessly modprobe the regulator driver on production > hardware, so doing it in the MFD driver and not registering the cell > seems best, I'm wondering if we can upgrade DSDT to provide _DSM for Aero platform. -- With Best Regards, Andy Shevchenko