From mboxrd@z Thu Jan 1 00:00:00 1970 From: Darren Hart Subject: Re: [PATCH] ACPI / GPIO: Pass index to acpi_get_gpiod_by_index() when using properties Date: Tue, 04 Nov 2014 15:42:38 -0800 Message-ID: <5459646E.9000707@linux.intel.com> References: <1414494927-204923-1-git-send-email-mika.westerberg@linux.intel.com> <2107668.8toVpPDgB1@vostro.rjw.lan> <3196606.Sy6xFg88zg@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <3196606.Sy6xFg88zg@vostro.rjw.lan> Sender: linux-kernel-owner@vger.kernel.org To: "Rafael J. Wysocki" , Grant Likely Cc: Mika Westerberg , Alexandre Courbot , Linus Walleij , Arnd Bergmann , ACPI Devel Mailing List , Linux Kernel Mailing List List-Id: linux-acpi@vger.kernel.org On 11/4/14 14:54, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > Subject: ACPI / property: Drop size_prop from acpi_dev_get_property_reference() > > The size_prop argument of the recently added function > acpi_dev_get_property_reference() is not used by the only current > caller of that function and is very unlikely to be used at any time > going forward. > > Namely, for a property whose value is a list of items each containing > a references to a device object possibly accompanied by some integers, > the number of items in the list can always be computed as the number > of elements of type ACPI_TYPE_LOCAL_REFERENCE in the property package. > Thus it should never be necessary to provide an additional "cells" > property with a value equal to the number of items in that list. In this case, do we never expect a property to contain more than one ACPI_TYPE_LOCAL_REFERENCE? Package () { "foobar", Package () { "PCI0.FOO", "PCI0.BAR", 0, 1, 0, "PCI0.FOO", "PCI0.BAR2", 0, 1, 1 } } This seems like it could be useful for connecting various types of devices together, but I confess not to have a specific exmaple in mind. It does concern me to limit the data format in this way. I suppose should such a case become necessary, we can deal with the issue then - and still avoid having a potential abuse point in the API from the start. -- Darren Hart Intel Open Source Technology Center