Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966070AbbDQOUP (ORCPT ); Fri, 17 Apr 2015 10:20:15 -0400 Received: from down.free-electrons.com ([37.187.137.238]:50968 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933010AbbDQOUG (ORCPT ); Fri, 17 Apr 2015 10:20:06 -0400 Date: Fri, 17 Apr 2015 16:19:22 +0200 From: Boris Brezillon To: Gregory CLEMENT Cc: Jason Cooper , Arnaud Ebalard , Mark Rutland , Thomas Petazzoni , Herbert Xu , Pawel Moll , Ian Campbell , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Eran Ben-Avi , Nadav Haklai , devicetree@vger.kernel.org, Rob Herring , Andrew Lunn , linux-crypto@vger.kernel.org, Kumar Gala , Tawfik Bayouk , "David S. Miller" , Lior Amsalem , Sebastian Hesselbarth Subject: Re: [PATCH 0/2] crypto: add new driver for Marvell CESA Message-ID: <20150417161922.54adec64@bbrezillon> In-Reply-To: <5531040D.4000007@free-electrons.com> References: <1428591523-1780-1-git-send-email-boris.brezillon@free-electrons.com> <20150410135056.GB28873@io.lakedaemon.net> <20150410171148.07bc9429@bbrezillon> <20150410223008.GA18660@io.lakedaemon.net> <552B8EC4.209@free-electrons.com> <20150413124711.GI18660@io.lakedaemon.net> <87r3rom2qu.fsf@natisbad.org> <20150413201146.GL18660@io.lakedaemon.net> <20150417103356.6ce78145@bbrezillon> <20150417103946.2a46c243@bbrezillon> <5531040D.4000007@free-electrons.com> X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.23; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2471 Lines: 69 Hi Gregory, On Fri, 17 Apr 2015 15:01:01 +0200 Gregory CLEMENT wrote: > Hi Boris, > > On 17/04/2015 10:39, Boris Brezillon wrote: > > On Fri, 17 Apr 2015 10:33:56 +0200 > > Boris Brezillon wrote: > > > >> Hi Jason, > >> > >> On Mon, 13 Apr 2015 20:11:46 +0000 > >> Jason Cooper wrote: > >> > >>>> > >>>>> I'd appreciate if we'd look into it. I understand from on-list and > >>>>> off-list discussion that the rewrite was unavoidable. So I'm willing to > >>>>> concede that. Giving people time to migrate from old to new while still > >>>>> being able to update for other security fixes seems reasonable. > >>>> > >>>> Jason, what do you think of the approach above? > >>> > >>> I say keep it simple. We shouldn't use the DT changes to trigger one > >>> vice the other. We need to be able to build both, but only load one at > >>> a time. If that's anything other than simple to do, then we make it a > >>> Kconfig binary choice and move on. > >> > >> Actually I was planning to handle it with a Kconfig dependency rule > >> (NEW_DRIVER depends on !OLD_DRIVER and OLD_DRIVER depends > >> on !NEW_DRIVER). > >> I don't know how to make it a runtime check without adding new > >> compatible strings for the kirkwood, dove and orion platforms, and I'm > >> sure sure this is a good idea. > > ^ not > > > >> Do you have any ideas ? > > You use devm_ioremap_resource() in the new driver, so if the old one > is already loaded the memory region will be already hold and the new > driver will simply fail during the probe. So for this part it is OK. I like the idea :-). > > However, the old driver doesn't try to reserve the region, it directly > uses an ioremap(). So if the new driver is loaded first, then the old > one will manage to be loaded too. I think that just adding a > request_region()/release_region() (or converting the ioremap in a > devm_ioremap_resource() in the old driver would be enough. Absolutely. Unless someone is opposed to this solution I think I'll choose this solution. Thanks, Boris -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/