Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935563AbdCJKbj (ORCPT ); Fri, 10 Mar 2017 05:31:39 -0500 Received: from foss.arm.com ([217.140.101.70]:54736 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935036AbdCJKbc (ORCPT ); Fri, 10 Mar 2017 05:31:32 -0500 Date: Fri, 10 Mar 2017 10:31:13 +0000 From: Brian Starkey To: Laura Abbott Cc: Benjamin Gaignard , Mark Brown , Michal Hocko , Sumit Semwal , Riley Andrews , Arve =?iso-8859-1?B?SGr4bm5lduVn?= , Rom Lemarchand , devel@driverdev.osuosl.org, Linux Kernel Mailing List , "linaro-mm-sig@lists.linaro.org" , Greg Kroah-Hartman , linux-arm-kernel@lists.infradead.org, "linux-media@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , Daniel Vetter , linux-mm@kvack.org Subject: Re: [RFC PATCH 00/12] Ion cleanup in preparation for moving out of staging Message-ID: <20170310103112.GA15945@e106950-lin.cambridge.arm.com> References: <1488491084-17252-1-git-send-email-labbott@redhat.com> <20170303132949.GC31582@dhcp22.suse.cz> <20170306074258.GA27953@dhcp22.suse.cz> <20170306104041.zghsicrnadoap7lp@phenom.ffwll.local> <20170306105805.jsq44kfxhsvazkm6@sirena.org.uk> <20170306160437.sf7bksorlnw7u372@phenom.ffwll.local> <26bc57ae-d88f-4ea0-d666-2c1a02bf866f@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <26bc57ae-d88f-4ea0-d666-2c1a02bf866f@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 873 Lines: 29 Hi, On Thu, Mar 09, 2017 at 09:38:49AM -0800, Laura Abbott wrote: >On 03/09/2017 02:00 AM, Benjamin Gaignard wrote: [snip] >> >> For me those patches are going in the right direction. >> >> I still have few questions: >> - since alignment management has been remove from ion-core, should it >> be also removed from ioctl structure ? > >Yes, I think I'm going to go with the suggestion to fixup the ABI >so we don't need the compat layer and as part of that I'm also >dropping the align argument. > Is the only motivation for removing the alignment parameter that no-one got around to using it for something useful yet? The original comment was true - different devices do have different alignment requirements. Better alignment can help SMMUs use larger blocks when mapping, reducing TLB pressure and the chance of a page table walk causing display underruns. -Brian