Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752050AbcDUNLO (ORCPT ); Thu, 21 Apr 2016 09:11:14 -0400 Received: from mail.kernel.org ([198.145.29.136]:59183 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751619AbcDUNLM (ORCPT ); Thu, 21 Apr 2016 09:11:12 -0400 MIME-Version: 1.0 In-Reply-To: <5718878A.8040901@huawei.com> References: <1458113743-15131-1-git-send-email-wangkefeng.wang@huawei.com> <5718878A.8040901@huawei.com> From: Rob Herring Date: Thu, 21 Apr 2016 08:10:48 -0500 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 all 00/14] use of_platform_default_populate() to populate default bus To: Kefeng Wang Cc: "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Arnd Bergmann , Shawn Guo , Catalin Marinas , Russell King - ARM Linux , Grant Likely , Olof Johansson , Masahiro Yamada , Hanjun Guo Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2752 Lines: 68 On Thu, Apr 21, 2016 at 2:55 AM, Kefeng Wang wrote: > Hi Rob, > > On 2016/4/20 5:10, Rob Herring wrote: >> On Wed, Mar 16, 2016 at 2:35 AM, Kefeng Wang wrote: >>> Use helper of_platform_default_populate() in linux/of_platform >>> when possible, instead of calling of_platform_populate() with >>> the default match table. >>> >>> Then it is possible for driver code build as a module, and no >>> need to export of_default_bus_match_table anymore. >>> >>> This patchset is based on Linux 4.5. >>> >>> Changes since v1: >>> - Add ack, test and review >>> - Remove v1 patch 14/15, the similar patch has posted and applied, >>> see https://patchwork.kernel.org/patch/8096991/ >>> >>> v1: >>> - https://lkml.org/lkml/2016/1/26/1123 >> >> I was going to apply this, but I've thought about this some more and >> it is a lot of tree wide churn for little gain. Most of the call sites >> here I want to get rid of by making of_platform_populate callable >> multiple times. The infrastructure is almost there, but I think we >> just need something like this: >> >> diff --git a/drivers/of/platform.c b/drivers/of/platform.c >> index 8d103e4..b25e710 100644 >> --- a/drivers/of/platform.c >> +++ b/drivers/of/platform.c >> @@ -345,6 +345,9 @@ static int of_platform_bus_create(struct device_node *bus, >> return 0; >> } >> >> + if (of_node_check_flag(bus, OF_POPULATED_BUS)) >> + return 0; >> + >> auxdata = of_dev_lookup(lookup, bus); >> if (auxdata) { >> bus_id = auxdata->name; >> >> Then we can call of_platform_populate from the DT core and remove all >> the default calls. > > OK, it seems that we can drop all the of_of_platform_default_populate in arch code > by this changes, will do it. > > But replace of_platform_populate() with the default match table by of_platform_default_populate > is a cleanup, and especially for the driver, we can not need export of_default_bus_match_table > after that. > > There is a v3 patchset[1], it is based 4.6-rc2 with some updated, should this be merge firstly, > then drop all the default of_platform_populate in arch code, and I think the of_iommu_init() in > arch code could do the same thing. > > If not, I will repost the patches with new ways, but still exists the part of unexport > of_default_bus_match_table by helper of_platform_default_populate(). > > Hope the v3 patchset could be merge in advance, after all, it has been reviewed fully. Thanks a lot. We'd be touching the same line twice in a bunch of places if we apply this series first, so it makes more sense to remove all these calls first and then use of_platform_default_populate where it is still needed. Rob