From mboxrd@z Thu Jan 1 00:00:00 1970 From: Darren Hart Subject: Re: [PATCH v2 1/3] platform: x86: dell-rbtn: Dell Airplane Mode Switch driver Date: Tue, 5 May 2015 22:55:46 -0700 Message-ID: <20150506055546.GA7523@vmdeb7> References: <1416755361-17357-1-git-send-email-pali.rohar@gmail.com> <20150430074429.GT24346@pali> <1828808.mVmCDTOvJh@xps13> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from bombadil.infradead.org ([198.137.202.9]:56122 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753502AbbEFFzt (ORCPT ); Wed, 6 May 2015 01:55:49 -0400 Content-Disposition: inline In-Reply-To: <1828808.mVmCDTOvJh@xps13> Sender: platform-driver-x86-owner@vger.kernel.org List-ID: To: Gabriele Mazzotta Cc: Pali =?iso-8859-1?Q?Roh=E1r?= , Alex Hung , Matthew Garrett , "platform-driver-x86@vger.kernel.org" , linux-kernel@vger.kernel.org On Tue, May 05, 2015 at 11:23:05PM +0200, Gabriele Mazzotta wrote: > On Thursday 30 April 2015 09:44:29 Pali Roh=E1r wrote: > > On Thursday 30 April 2015 14:06:27 Alex Hung wrote: > > > Method ABRT is to be used by driver to disable BIOS handling of r= adio > > > button. So the changes in behaviours observed by Gabriele is expe= cted. > > > I have seen other systems behave the same way. > > >=20 > >=20 > > Right, that after that ARBT call operating system get full control = over > > radio devices and ACPI/BIOS will not automatically enable/disable t= hem. > > I think this is OK. > >=20 > > But for that we need also support for manually enable/disable radio > > devices and code for this support is missing. Or do DELLABCE/RBTN a= cpi > > devices somehow support enabling/disabling it via system/kernel req= uest? > >=20 > > > I do also see firmware only sends Notify(RBTN, 0x80) and no hard = block > > > whether ABRT(1) is called or not. Thus keycode are the only opti= on on > > > those machines. > > >=20 > >=20 > > Key is ok, but we *must* have ability to hard block it via some > > ACPI/WMI/BIOS/FW/etc... call. Otherwise ARBT(1) is no go as users s= hould > > be able to enable/disable their radio devices (bluetooth for powers= ave) >=20 > Does it really matter in the end? As I understand it, radio devices a= re > off either way. As a point of reference for consideration, we recently dropped the Thin= kpad hardware mute button because it seriously complicated everything in wha= t appears to be a similar sort of situation. By eliminating the hardware mute and= relying purely on software mute, we were able to provide a much more consistent= ly functional driver. Also note that this driver provided a "software_mute" module parameter = to allow the user to control this. I believe this provides some relevant precedent for your consideration.= I don't want to add parameters casually, but it could be one is warranted here. --=20 Darren Hart Intel Open Source Technology Center