From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755895AbaCNTLC (ORCPT ); Fri, 14 Mar 2014 15:11:02 -0400 Received: from moutng.kundenserver.de ([212.227.126.131]:61085 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755085AbaCNTK6 (ORCPT ); Fri, 14 Mar 2014 15:10:58 -0400 From: Arnd Bergmann To: Liviu Dudau Subject: Re: [PATCH v7 3/3] arm64: Add architecture support for PCI Date: Fri, 14 Mar 2014 20:10:39 +0100 User-Agent: KMail/1.12.2 (Linux/3.8.0-22-generic; KDE/4.3.2; x86_64; ; ) Cc: Catalin Marinas , "linux-pci" , Bjorn Helgaas , Will Deacon , Benjamin Herrenschmidt , "linaro-kernel" , LKML , "devicetree@vger.kernel.org" , LAKML , Tanmay Inamdar , Grant Likely References: <1394811258-1500-1-git-send-email-Liviu.Dudau@arm.com> <201403141838.08900.arnd@arndb.de> <20140314180527.GZ6457@e106497-lin.cambridge.arm.com> In-Reply-To: <20140314180527.GZ6457@e106497-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <201403142010.39886.arnd@arndb.de> X-Provags-ID: V02:K0:ysy7IQqfkAj4vMut+DNAevOiNIGx4DLDYw5d++iD34j tn/YpClw+D6LQXKp3VMBJev1+DZYtL/3wFRPeS17he7DsM1qML A6CEwSomZ6jGuoakig2bVfDP1dwxelYs8ZNoWCfx3vw313nNCQ vJU1bq23aifWtjsCoid7kDpp+GSlrTBzxs5JK5Tq3+LBYdaQPj T8KkIIa4uizwNUk26htl9BZ3zEVZ7bAigYhfbT0g0QePHgj+B/ CEuSedi20MRHxYCyjijyaQSERbmLEMIksyFLWItA9gH/IMgpyB asIdjC8J8vv5ZLfPdrjOVJGKE7448cTK9EG6jPLAXEO99+BNs3 K8sdsjUd235o1+ZUeKcEtt613MS51QGR5za2ySh4a Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 14 March 2014, Liviu Dudau wrote: > > > > I haven't seen any reaction from Bjorn on this, so I threaded carefully on that > subject. I'm new to this so I don't know how to handle this. > > To my mind, and looking at the way every architecture has been setup, the pcibios_* > function are intended to be provided by the architecture. That is definitely correct. > No matter how much wishful > thinking we are going to put in here, it will not change the fact that the non-arm64 > specific version of pcibios_fixup_bus() that I wrote is not shared by anyone else > and it will remain "for arm64 use only" regardless to where it is placed until the > next architecture comes into the kernel. And even then its adoption is questionable. Agreed as well. > If we are looking for simple and common implementations of this function, maybe we > should look at why microblaze and powerpc versions, that are identical, are not being > made the default __weak implementation. Microblaze could most likely just be moved over to your version. The only reason it is shared with the powerpc implementation is that they were anticipating the code to become shared again and that it was known to be working with flattened device tree. > As for the other two functions, I've no special attachment to where they are present > and I'm happy to move them into drivers/pci on the condition that the patchset doesn't > double in size. The reason why I'm weary of touching other architectures in a significant > way is the current lack of engineering bandwidth and way of testing all the architectures. > My low friction approach has been to introduce them in arm64 and then slowly move them > into core (and yes, I know about good intentions and the road to hell.) I think everyone working on PCI is fed up with having arch-specific implementations of all these, and Bjorn has been very supportive of generic infrastructure in the past. Even just adding a generic infrastructure in a common place that is used only by one architecture in my mind would be a significant improvement. Arnd