From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751845AbdC0Awn (ORCPT ); Sun, 26 Mar 2017 20:52:43 -0400 Received: from mga03.intel.com ([134.134.136.65]:53837 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751633AbdC0Awf (ORCPT ); Sun, 26 Mar 2017 20:52:35 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,229,1486454400"; d="scan'208";a="1127385671" Subject: Re: [PATCH v1] Revert "extcon: usb-gpio: add support for ACPI gpio interface" To: Chanwoo Choi , Andy Shevchenko , linux-kernel@vger.kernel.org, MyungJoo Ham References: <20170321183747.32450-1-andriy.shevchenko@linux.intel.com> <58D1D00F.40300@samsung.com> <1490188199.19767.164.camel@linux.intel.com> <58D4FCF8.9010509@samsung.com> <1490354699.21738.1.camel@linux.intel.com> <1f01d7e8-de18-98c3-ddad-2cae5a9f6421@samsung.com> From: Lu Baolu Message-ID: <58D86200.9050806@linux.intel.com> Date: Mon, 27 Mar 2017 08:51:12 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <1f01d7e8-de18-98c3-ddad-2cae5a9f6421@samsung.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 03/24/2017 07:47 PM, Chanwoo Choi wrote: > Hi Lu Baolu, > > On 2017년 03월 24일 20:24, Andy Shevchenko wrote: >> On Fri, 2017-03-24 at 20:03 +0900, Chanwoo Choi wrote: >>> On 2017년 03월 22일 22:09, Andy Shevchenko wrote: >>>> On Wed, 2017-03-22 at 10:14 +0900, Chanwoo Choi wrote: >>>>> On 2017년 03월 22일 03:37, Andy Shevchenko wrote: >>>>>> The commit 942c7924a51e introduced a check for ACPI handle for >>>>>> the >>>>>> device that never appears on any ACPI-enabled platform so far. >>>>>> It >>>>>> seems >>>>>> a confusion with extcon-intel-int3496 which does support ACPI- >>>>>> enabled >>>>>> platforms. >>>>> Only for the reason that there is no any usecase until now, >>>>> and remove the confusion between extcon-usb-gpio and extcon-intel- >>>>> int3496. >>>>> Should we revert it? >>>> >>>>> I think that both extcon-usb-gpio and extcon-intel-int3496 >>>>> driver are not same operation perfectly. Also, the filename >>>>> of extcon-intel-int3496 has specific name. Instead, extcon-usb- >>>>> gpio.c >>>>> is more common device driver. >>>>> >>>>> Can the extcon-intel-int3496.c support the everything on acpi >>>>> side? >>>> For my understanding we have the only driver for now for USB mux in >>>> the >>>> kernel for ACPI-enabled platforms. >>>> >>>> Besides confusion, it makes harder to fix a real bugs in at least >>>> GPIO >>>> ACPI library since we need to amend any user of it first. While >>>> confusion is here, I can't do anything to not possible break the >>>> functionality of the driver in a real use case if any (I doubt there >>>> is >>>> any in this particular case). >>>> >>>> So, my opinion here is "yes, we should revert it until we have a >>>> confirmation that there is a product which is using this among with >>>> ACPI" (which I doubt ever exists). >>> Because you told me there was not any use case of extcon-usb-gpioc.c >>> on acpi side. But, I think that it is not enough as the reason. >>> >>> Because I already mentioned, >>> 1. >>> "The both extcon-usb-gpio and extcon-intel-int3496 driver >>> are not same operation perfectly." It two driver are same operation >>> and there is no use case on acpi side, I may agree your suggestion. >>> But, in this case, they are different between two drivers. >>> >>> 2. >>> Also, extcon-intel-int3496 has the specific name 'int3496'. >>> I think that it only depends on the specific device driver on acpi >>> side. >>> I don't think it cover all of use case on acpi side. >> Just one question: is there *real* existing device where ACPI table >> contains something related to extcon-usb-gpio? >> >> I'm pretty sure the answer is no. Moreover, Lu pointed me out to the >> series which tried to update the driver in question to support int3496. >> Though it comes as a separate driver, thus that series was abandoned >> IIUC. >> >> I really don't care if some dead confusing code will be left in some >> poor driver, at the end it's not my call. >> >> P.S. We already spent enough time making a mountain out of a molehill. I >> rest my case. >> > OK. Just I want to receive the reply from Lu Baolu. > > In the "extcon-usb-gpio ACPI support" mail thread, > I understood that Lu Baolu said that the related patches were abandoned. > > To Lu Baolu, > Don't you ever use the extcon-usb-gpio.c in the future on acpi side? > If you agree it, I'll revert it. > I will not use extcon-usb-gpio.c in the future on acpi side AFAICS. Best regards, Lu Baolu