From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751356AbcBHIuh (ORCPT ); Mon, 8 Feb 2016 03:50:37 -0500 Received: from mail-wm0-f42.google.com ([74.125.82.42]:36451 "EHLO mail-wm0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750829AbcBHIuf (ORCPT ); Mon, 8 Feb 2016 03:50:35 -0500 Date: Mon, 8 Feb 2016 09:50:25 +0100 From: Pali =?utf-8?B?Um9ow6Fy?= To: Sebastian Reichel Cc: Tony Lindgren , =?utf-8?Q?Beno=C3=AEt?= Cousson , Aaro Koskinen , Pavel Machek , linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, Ivaylo Dimitrov Subject: Re: [PATCH 4/5] HSI: nokia-modem: drop support for disabled pm Message-ID: <20160208085025.GA30075@pali> References: <1454203187-688-1-git-send-email-sre@kernel.org> <1454203187-688-5-git-send-email-sre@kernel.org> <201601311224.34249@pali> <20160131161052.GA16550@earth> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20160131161052.GA16550@earth> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sunday 31 January 2016 17:10:52 Sebastian Reichel wrote: > Hi, > > On Sun, Jan 31, 2016 at 12:24:34PM +0100, Pali Rohár wrote: > > On Sunday 31 January 2016 02:19:46 Sebastian Reichel wrote: > > > Disabled power management means, that the driver can only be > > > used together with further out-of-tree kernel patches. There > > > is no reason to support this in the mainline kernel and not > > > having support for it means, that userspace can automatically > > > detect if we are running kernel based power management. > > > > I'm against this change. It will break support for (patched) Maemo and > > proprietary Nokia sscd modem daemon. > > Do you have some links for this? So far my assumption was, that sscd > requires /sys/devices/platform/gpio-switch, so you either need to > patch sscd somehow, or patch the kernel to provide gpio-switch, or > provide some kind of userspace wrapper. I can either patch kernel to provide gpio-switch interface or use some kind of user space hacks to provide this interface (e.g mount bind or fuse fs mounted to that location). > > Also you can export GPIOs manually via sysfs and touch that state. Which > > means that you can do power management with mainline kernel even if you > > set nokia-modem.pm=0. > > Yeah... You export GPIOs manually. Did you actually try this? You Yes, this is what preinit script is doing. > will end up with exactly the same result as nokia-modem.pm=1, just > with a few less symlinks. Also you have to make sure, that you > actually exported the right gpios, since the global gpio number is > dependent on the gpio-controller registration order. > > > So please drop this patch. > > Please provide facts, that Maemo can use pm=0 without additional > kernel patches and does not work with pm=1. Currently we use simple kernel driver which register gpio-switch interface. Why to remove something which is 1) working and is 2) useful for users & developers? -- Pali Rohár pali.rohar@gmail.com