From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755495Ab3KLOIL (ORCPT ); Tue, 12 Nov 2013 09:08:11 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:50572 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754727Ab3KLOIJ (ORCPT ); Tue, 12 Nov 2013 09:08:09 -0500 From: "Rafael J. Wysocki" To: Mika Westerberg Cc: Lan Tianyu , ACPI Devel Maling List , LKML , Linux PCI , Greg Kroah-Hartman , Bjorn Helgaas , Aaron Lu , Jarkko Nikula , "Luck, Tony" Subject: Re: [PATCH] ACPI / driver core: Store a device pointer in struct acpi_dev_node Date: Tue, 12 Nov 2013 15:20:37 +0100 Message-ID: <3448237.NUtWjlv2Mb@vostro.rjw.lan> User-Agent: KMail/4.10.5 (Linux/3.12.0-rc6+; KDE/4.10.5; x86_64; ; ) In-Reply-To: <20131112092402.GO22916@intel.com> References: <3268437.YsusHvklcv@vostro.rjw.lan> <1683079.zjqzsOAjXB@vostro.rjw.lan> <20131112092402.GO22916@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday, November 12, 2013 11:24:02 AM Mika Westerberg wrote: > On Mon, Nov 11, 2013 at 02:45:39PM +0100, Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki > > Subject: ACPI / driver core: Store an ACPI device pointer in struct acpi_dev_node > > > > Modify struct acpi_dev_node to contain a pointer to struct acpi_device > > associated with the given device object (that is, its ACPI companion > > device) instead of an ACPI handle corresponding to it. Introduce two > > new macros for manipulating that pointer in a CONFIG_ACPI-safe way, > > ACPI_COMPANION() and ACPI_COMPANION_SET(), and rework the > > ACPI_HANDLE() macro to take the above changes into account. > > Drop the ACPI_HANDLE_SET() macro entirely and rework its users to > > use ACPI_COMPANION_SET() instead. For some of them who used to > > pass the result of acpi_get_child() directly to ACPI_HANDLE_SET() > > introduce a helper routine acpi_preset_companion() doing an > > equivalent thing. > > > > The main motivation for doing this is that there are things > > represented by struct acpi_device objects that don't have valid > > ACPI handles (so called fixed ACPI hardware features, such as > > power and sleep buttons) and we would like to create platform > > device objects for them and "glue" them to their ACPI companions > > in the usual way (which currently is impossible due to the > > lack of valid ACPI handles). However, there are more reasons > > why it may be useful. > > > > First, struct acpi_device pointers allow of much better type checking > > than void pointers which are ACPI handles, so it should be more > > difficult to write buggy code using modified struct acpi_dev_node > > and the new macros. Second, the change should help to reduce (over > > time) the number of places in which the result of ACPI_HANDLE() is > > passed to acpi_bus_get_device() in order to obtain a pointer to the > > struct acpi_device associated with the given "physical" device, > > because now that pointer is returned by ACPI_COMPANION() directly. > > Finally, the change should make it easier to write generic code that > > will build both for CONFIG_ACPI set and unset without adding explicit > > compiler directives to it. > > > > Signed-off-by: Rafael J. Wysocki > > I tested this on Haswell as well and it works fine with ACPI enumerated > platform, I2C and SPI devices. > > Tested-by: Mika Westerberg (on Haswell) > Reviewed-by: Mika Westerberg Thanks! -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.