From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH] iommu: exynos: pointers are nto physical addresses Date: Mon, 29 Feb 2016 10:54:49 +0100 Message-ID: <26472865.zD5Ep58Exn@wuerfel> References: <1456735568-3886545-1-git-send-email-arnd@arndb.de> <56D41087.60506@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: Received: from mout.kundenserver.de ([217.72.192.75]:49212 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750855AbcB2Jzc (ORCPT ); Mon, 29 Feb 2016 04:55:32 -0500 In-Reply-To: <56D41087.60506@samsung.com> Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Marek Szyprowski Cc: Joerg Roedel , Joerg Roedel , Kukjin Kim , Krzysztof Kozlowski , linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org On Monday 29 February 2016 10:33:59 Marek Szyprowski wrote: > > --- > > I also see that some incorrect __raw_writel() calls have crept in > > around the same time, which breaks running big-endian kernels when > > this driver is loaded. > > > > Please fix and that that as well. > > Okay, so in the driver code all __raw_writel should be replaced by > writel(), right? Yes, writel() is always the safe choice if you don't know what to use. __raw_writel() should be considered an implementation detail and not used in drivers at all. There is also writel_relaxed(), which is faster than writel() because it leaves out all the barriers (as __raw_writel does too), and you can sometimes use that in the fast path if you can prove that no barriers are needed. Arnd