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=-9.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 66EEBC35257 for ; Fri, 2 Oct 2020 17:55:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 03AA52145D for ; Fri, 2 Oct 2020 17:55:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="tyQZ83BX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387934AbgJBRzF (ORCPT ); Fri, 2 Oct 2020 13:55:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726096AbgJBRzF (ORCPT ); Fri, 2 Oct 2020 13:55:05 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C41F0C0613D0; Fri, 2 Oct 2020 10:55:04 -0700 (PDT) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id BE0D72A2; Fri, 2 Oct 2020 19:55:00 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1601661300; bh=Qf5HRVHyIghCAni0kFGOWiS+pLkA33+NJPB9Z0/mkIM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tyQZ83BXpSGafZKcDDYw5h9fnxWiy6R8cB193qxbzdZznN7LBrciEoZTVFUOZBMl+ FhKB8srgeqVzZ6BUphAZ4AsgJnwvg2ebbaPIQLjtfq5ywom1UnaILbMF0sDMhDMUZN jYIXxfd4B3aItZkQnYX08/FGcSHjOKgL+FOVFb4U= Date: Fri, 2 Oct 2020 20:54:23 +0300 From: Laurent Pinchart To: Saravana Kannan Cc: Rob Herring , Frank Rowand , Geert Uytterhoeven , Greg Kroah-Hartman , Grygorii Strashko , linux-omap , "open list:THERMAL" , Peter Ujfalusi , "Rafael J. Wysocki" , Tomi Valkeinen , Tony Lindgren , Ulf Hansson , Android Kernel Team , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v1] of: platform: Batch fwnode parsing in the init_machine() path Message-ID: <20201002175423.GE3933@pendragon.ideasonboard.com> References: <20201001225952.3676755-1-saravanak@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org Hi Saravana, On Fri, Oct 02, 2020 at 10:51:51AM -0700, Saravana Kannan wrote: > On Fri, Oct 2, 2020 at 7:08 AM Rob Herring wrote: > > On Thu, Oct 1, 2020 at 5:59 PM 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(). > > > > > > Reported-by: Tomi Valkeinen > > > Signed-off-by: Saravana Kannan > > > --- > > > drivers/of/platform.c | 19 +++++++++++++++---- > > > 1 file changed, 15 insertions(+), 4 deletions(-) > > > > > > diff --git a/drivers/of/platform.c b/drivers/of/platform.c > > > index 071f04da32c8..79972e49b539 100644 > > > --- a/drivers/of/platform.c > > > +++ b/drivers/of/platform.c > > > @@ -501,8 +501,21 @@ int of_platform_default_populate(struct device_node *root, > > > const struct of_dev_auxdata *lookup, > > > struct device *parent) > > > { > > > - return of_platform_populate(root, of_default_bus_match_table, lookup, > > > - parent); > > > + int ret; > > > + > > > + /* > > > + * fw_devlink_pause/resume() are only safe to be called around top > > > + * level device addition due to locking constraints. > > > + */ > > > + if (!root) > > > + fw_devlink_pause(); > > > + > > > + ret = of_platform_populate(root, of_default_bus_match_table, lookup, > > > + parent); > > > > of_platform_default_populate() vs. of_platform_populate() is just a > > different match table. I don't think the behavior should otherwise be > > different. > > > > There's also of_platform_probe() which has slightly different matching > > behavior. It should not behave differently either with respect to > > devlinks. > > So I'm trying to do this only when the top level devices are added for > the first time. of_platform_default_populate() seems to be the most > common path. For other cases, I think we just need to call > fw_devlink_pause/resume() wherever the top level devices are added for > the first time. As I said in the other email, we can't add > fw_devlink_pause/resume() by default to of_platform_populate(). > > Do you have other ideas for achieving "call fw_devlink_pause/resume() > only when top level devices are added for the first time"? I'm not an expert in this domain, but before investigating it, would you be able to share a hack patch that implements this (in the most simple way) to check if it actually fixes the delays I experience on my system ? -- Regards, Laurent Pinchart