From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v3 10/15] leds: leds-gpio: Add ACPI probing support Date: Wed, 01 Oct 2014 20:22:36 +0200 Message-ID: <15084898.uePkciO2J1@wuerfel> References: <1410868367-11056-1-git-send-email-mika.westerberg@linux.intel.com> <20141001163025.GE23115@dtor-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: Received: from mout.kundenserver.de ([212.227.126.131]:58428 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751432AbaJASWt (ORCPT ); Wed, 1 Oct 2014 14:22:49 -0400 In-Reply-To: Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Darren Hart Cc: Dmitry Torokhov , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Mika Westerberg , linux-acpi@vger.kernel.org, devicetree@vger.kernel.org, Greg Kroah-Hartman , Linus Walleij , Alexandre Courbot , Bryan Wu , Lee Jones , Grant Likely , Aaron Lu On Wednesday 01 October 2014 11:11:46 Darren Hart wrote: > > > >No, I think in absence of drv->acpi_match_table ACPI core should just go > >and > >use drv->of_match_table to do the matching and be done with it. > > But then you will match drivers that have of-only support that don't know > anything about ACPI and haven't been updated to use the new API. Worse, > some of those drivers will assume of node structs and such and potentially > panic. Unless I'm sorry mistaken here.... > I don't think that is a huge danger: most drivers tend to check for the presence of dev->of_node before calling any of the DT interfaces, you'd only ever enter the probe function if the compatible string matches (i.e. an old kernel with a new ACPI table), and most users of ACPI systems will disable CONFIG_OF at compile time, so the accessors looking at the of_node are not there. In theory it's possible that something goes wrong here, but it's not very likely to ever cause problems. Arnd