From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933919AbcHaLtA (ORCPT ); Wed, 31 Aug 2016 07:49:00 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:36326 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933252AbcHaLs4 (ORCPT ); Wed, 31 Aug 2016 07:48:56 -0400 Date: Wed, 31 Aug 2016 13:48:47 +0200 From: Peter Zijlstra To: Matt Redfearn Cc: Ralf Baechle , linux-mips@linux-mips.org, Adam Buchbinder , Arnd Bergmann , Masahiro Yamada , linux-kernel@vger.kernel.org, "Michael S. Tsirkin" , Markos Chandras , Paul Burton Subject: Re: [PATCH 06/10] MIPS: pm-cps: Use MIPS standard lightweight ordering barrier Message-ID: <20160831114847.GB10153@twins.programming.kicks-ass.net> References: <1472640279-26593-1-git-send-email-matt.redfearn@imgtec.com> <1472640279-26593-7-git-send-email-matt.redfearn@imgtec.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1472640279-26593-7-git-send-email-matt.redfearn@imgtec.com> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 31, 2016 at 11:44:35AM +0100, Matt Redfearn wrote: > Since R2 of the MIPS architecture, SYNC(0x10) has been an optional but > architecturally defined ordering barrier. If a CPU does not implement it, > the arch specifies that it must fall back to SYNC(0). > > Define the barrier type and always use it in the pm-cps code rather than > falling back to the heavyweight sync(0) such that we can benefit from > the lighter weight sync. > Changelog does not explain what 0x10 is, nor why its sufficient for this case. Changelog also fails to explain why you do this. How do you expect anybody to review this?