From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E6863C46466 for ; Fri, 2 Oct 2020 18:11:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A6A5220719 for ; Fri, 2 Oct 2020 18:11:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="idPX+Snt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387602AbgJBSLn (ORCPT ); Fri, 2 Oct 2020 14:11:43 -0400 Received: from fllv0015.ext.ti.com ([198.47.19.141]:59866 "EHLO fllv0015.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726017AbgJBSLm (ORCPT ); Fri, 2 Oct 2020 14:11:42 -0400 Received: from lelv0265.itg.ti.com ([10.180.67.224]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id 092IBSqr092465; Fri, 2 Oct 2020 13:11:28 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1601662288; bh=FrG+09mt+C6MwBdbdxNRK4ndGXEpqzZKrDi9Tb3hMr4=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=idPX+SntM348a4zjFy3y23URBnUA3fN5DgNzf35MZqeH5/ImNtli4IFyIVy8s5rPX QytTtST7OVYXmQvNkH/ullG5IdtdHa0O1WOR7qfmtkqZwqMD/vXrc5/6ug+1pA3YO0 zOJ1A43sA3T5jEszN2giQy6h4qOQGxBqyxCmlw30= Received: from DFLE103.ent.ti.com (dfle103.ent.ti.com [10.64.6.24]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 092IBSj5031587 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 2 Oct 2020 13:11:28 -0500 Received: from DFLE107.ent.ti.com (10.64.6.28) by DFLE103.ent.ti.com (10.64.6.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3; Fri, 2 Oct 2020 13:11:28 -0500 Received: from lelv0326.itg.ti.com (10.180.67.84) by DFLE107.ent.ti.com (10.64.6.28) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3 via Frontend Transport; Fri, 2 Oct 2020 13:11:28 -0500 Received: from [10.250.100.73] (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0326.itg.ti.com (8.15.2/8.15.2) with ESMTP id 092IBN8W122280; Fri, 2 Oct 2020 13:11:24 -0500 Subject: Re: [PATCH v1] of: platform: Batch fwnode parsing in the init_machine() path To: Saravana Kannan CC: Laurent Pinchart , Rob Herring , Frank Rowand , Geert Uytterhoeven , Greg Kroah-Hartman , Linux-OMAP , Linux PM , Peter Ujfalusi , "Rafael J. Wysocki" , Tomi Valkeinen , Tony Lindgren , Ulf Hansson , Android Kernel Team , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , LKML References: <20201001225952.3676755-1-saravanak@google.com> <20201001231922.GG3722@pendragon.ideasonboard.com> <17bdc3f0-d816-151a-fef2-88cd38fc8621@ti.com> From: Grygorii Strashko Message-ID: <65bfd5be-8a10-4575-41a5-94e2f4ca2729@ti.com> Date: Fri, 2 Oct 2020 21:11:21 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On 02/10/2020 20:48, Saravana Kannan wrote: > On Fri, Oct 2, 2020 at 8:03 AM 'Grygorii Strashko' via kernel-team > wrote: >> >> >> >> On 02/10/2020 14:40, Grygorii Strashko wrote: >>> >>> >>> On 02/10/2020 02:19, Laurent Pinchart wrote: >>>> Hi Saravana, >>>> >>>> Thank you for the patch. >>>> >>>> On Thu, Oct 01, 2020 at 03:59:51PM -0700, Saravana Kannan wrote: >>>>> When commit 93d2e4322aa7 ("of: platform: Batch fwnode parsing when >>>>> adding all top level devices") optimized the fwnode parsing when all top >>>>> level devices are added, it missed out optimizing this for platform >>>>> where the top level devices are added through the init_machine() path. >>>>> >>>>> This commit does the optimization for all paths by simply moving the >>>>> fw_devlink_pause/resume() inside of_platform_default_populate(). >>>> >>>> Based on v5.9-rc5, before the patch: >>>> >>>> [ 0.652887] cpuidle: using governor menu >>>> [ 12.349476] No ATAGs? >>>> >>>> After the patch: >>>> >>>> [ 0.650460] cpuidle: using governor menu >>>> [ 12.262101] No ATAGs? >>>> >>>> :-( >>> >>> This is kinda expected :( because omap2 arch doesn't call of_platform_default_populate() >>> >>> Call path: >>> board-generic.c >>> DT_MACHINE_START() >>> .init_machine = omap_generic_init, >>> >>> omap_generic_init() >>> pdata_quirks_init(omap_dt_match_table); >>> of_platform_populate(NULL, omap_dt_match_table, >>> omap_auxdata_lookup, NULL); >>> >>> Other affected platforms >>> arm: mach-ux500 >>> some mips >>> some powerpc >>> >>> there are also case when a lot of devices placed under bus node, in such case >>> of_platform_populate() calls from bus drivers will also suffer from this issue. >>> >>> I think one option could be to add some parameter to _populate() or introduce new api. >>> >>> By the way, is there option to disable this feature at all? >>> Is there Kconfig option? >>> Is there any reasons why such complex and time consuming code added to the kernel and not implemented on DTC level? >>> >>> >>> Also, I've came with another diff, pls check. >>> >>> [ 0.000000] Booting Linux on physical CPU 0x0 >>> [ 0.000000] Linux version 5.9.0-rc6-01791-g9acba6b38757-dirty (grygorii@grygorii-XPS-13-9370) (arm-linux-gnueabihf-gcc (GNU Toolcha0 >>> [ 0.000000] CPU: ARMv7 Processor [412fc0f2] revision 2 (ARMv7), cr=10c5387d >>> [ 0.000000] CPU: div instructions available: patching division code >>> [ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, PIPT instruction cache >>> [ 0.000000] OF: fdt: Machine model: TI AM5718 IDK >>> ... >>> [ 0.053443] cpuidle: using governor ladder >>> [ 0.053470] cpuidle: using governor menu >>> [ 0.089304] No ATAGs? >>> ... >>> [ 3.092291] devtmpfs: mounted >>> [ 3.095804] Freeing unused kernel memory: 1024K >>> [ 3.100483] Run /sbin/init as init process >>> >>> >>> >>> ------ >< --- >>> diff --git a/drivers/of/platform.c b/drivers/of/platform.c >>> index 071f04da32c8..4521b26e7745 100644 >>> --- a/drivers/of/platform.c >>> +++ b/drivers/of/platform.c >>> @@ -514,6 +514,12 @@ static const struct of_device_id reserved_mem_matches[] = { >>> {} >>> }; >>> >>> +static int __init of_platform_fw_devlink_pause(void) >>> +{ >>> + fw_devlink_pause(); >>> +} >>> +core_initcall(of_platform_fw_devlink_pause); >>> + >>> static int __init of_platform_default_populate_init(void) >>> { >>> struct device_node *node; >>> @@ -538,9 +544,7 @@ static int __init of_platform_default_populate_init(void) >>> } >>> >>> /* Populate everything else. */ >>> - fw_devlink_pause(); >>> of_platform_default_populate(NULL, NULL, NULL); >>> - fw_devlink_resume(); >>> >>> return 0; >>> } >>> @@ -548,6 +552,7 @@ arch_initcall_sync(of_platform_default_populate_init); >>> >>> static int __init of_platform_sync_state_init(void) >>> { >>> + fw_devlink_resume(); >> >> ^ it seems has to be done earlier, like >> +static int __init of_platform_fw_devlink_resume(void) >> +{ >> + fw_devlink_resume(); >> + return 0; >> +} >> +device_initcall_sync(of_platform_fw_devlink_resume); > > This will mean no device will probe until device_initcall_sync(). > Unfortunately, I don't think we can make such a sweeping assumption. Could you answer below questions, pls? >>> By the way, is there option to disable this feature at all? >>> Is there Kconfig option? -- Best regards, grygorii