Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752295AbdIEQyL (ORCPT ); Tue, 5 Sep 2017 12:54:11 -0400 Received: from foss.arm.com ([217.140.101.70]:42854 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751480AbdIEQyJ (ORCPT ); Tue, 5 Sep 2017 12:54:09 -0400 Cc: Sudeep Holla , Nishanth Menon , Harb Abdulhamid , Arnd Bergmann , Jassi Brar , Ryan Harkin , Roy Franz , Loc Ho , Alexey Klimov Subject: Re: [PATCH v2 05/18] firmware: arm_scmi: add initial support for performance protocol To: Julien Thierry , ALKML , LKML , DTML References: <1501857104-11279-1-git-send-email-sudeep.holla@arm.com> <1501857104-11279-6-git-send-email-sudeep.holla@arm.com> <2690239b-27a7-dce3-88a6-d53808e8e93c@arm.com> <534bae20-9f80-e79b-42a5-93d838732720@arm.com> From: Sudeep Holla Organization: ARM Message-ID: Date: Tue, 5 Sep 2017 17:54:43 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <534bae20-9f80-e79b-42a5-93d838732720@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 794 Lines: 31 Hi Julien, On 05/09/17 16:56, Julien Thierry wrote: > > > On 05/09/17 16:04, Julien Thierry wrote: [...] >> >> This seems odd, shouldn't it be the following? >> le64_to_cpu(attr->stats_addr_low | (__le64)attr->stats_addr_high << 32) >> > > After further reflexion, I think you are right. If I understood the > specification, the address seems to be split into upper and lower 32bits > and each one is stored as a uint32, which fits what you are doing to > obtain the address. > > You can ignore my previous comment. > Sorry I am checking this bit late, you have figured out yourself already. All the 64 bit values need to be dealt similarly as SCMI specification restricts so. It's basically done so as the firmware running is mostly 32-bit little endian system. -- Regards, Sudeep