From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756742AbdCXLbZ (ORCPT ); Fri, 24 Mar 2017 07:31:25 -0400 Received: from mga04.intel.com ([192.55.52.120]:31799 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751811AbdCXLbS (ORCPT ); Fri, 24 Mar 2017 07:31:18 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,214,1486454400"; d="scan'208";a="947779266" Message-ID: <1490354699.21738.1.camel@linux.intel.com> Subject: Re: [PATCH v1] Revert "extcon: usb-gpio: add support for ACPI gpio interface" From: Andy Shevchenko To: Chanwoo Choi , linux-kernel@vger.kernel.org, MyungJoo Ham Cc: Lu Baolu Date: Fri, 24 Mar 2017 13:24:59 +0200 In-Reply-To: <58D4FCF8.9010509@samsung.com> References: <20170321183747.32450-1-andriy.shevchenko@linux.intel.com> <58D1D00F.40300@samsung.com> <1490188199.19767.164.camel@linux.intel.com> <58D4FCF8.9010509@samsung.com> Organization: Intel Finland Oy Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6-1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. -- Andy Shevchenko Intel Finland Oy