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=-18.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_IN_DEF_DKIM_WL 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 16359C43381 for ; Wed, 10 Feb 2021 08:59:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C729764E2F for ; Wed, 10 Feb 2021 08:59:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229768AbhBJI6x (ORCPT ); Wed, 10 Feb 2021 03:58:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54540 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229799AbhBJI4M (ORCPT ); Wed, 10 Feb 2021 03:56:12 -0500 Received: from mail-yb1-xb32.google.com (mail-yb1-xb32.google.com [IPv6:2607:f8b0:4864:20::b32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B5E7DC06178A for ; Wed, 10 Feb 2021 00:55:31 -0800 (PST) Received: by mail-yb1-xb32.google.com with SMTP id m188so712563yba.13 for ; Wed, 10 Feb 2021 00:55:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=EIYUBkGMy3qE6aqOle/QpEgFxQFoJfY+aVajMelV3xs=; b=qqKG0XSv+akp+PhEDy+mWsosrzGxxmJtkSfE/RiAHtParBQ1+/HeO672kBHv8o8i3G eesnT9wcGJbvHbEc1b+g2cn0zA0r/mdAvB5O6SsxerFnvgsLpiD28pUxjoC2ILa9euYV xYnXmOzzgBvMfFgJOHoRR+nS/1qfbPS4DJMg3ElQZbbZMS9S72aPCJBFR1jKl5o7SEK9 gRY86ph1NI9lK898i7M4Bbmis02HInlo2BaYGfBFxcGzfZwvNSrCXXoPaZIT3IgxwxES KbI+yTrvPRW7RVetJNStLFzDlDblpefA1Q7CbbkLfvL9z8TfDasFOAyUL0v8uoBv3qq/ JRYA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=EIYUBkGMy3qE6aqOle/QpEgFxQFoJfY+aVajMelV3xs=; b=JR4/vaj6PEnznSFYGw0SS8WZa+R0s6FNM1wOlN4yA27UiFIBddF6mfg27a9Fpjae8t j/P/9y17Q0pgHQO3nycMjvG72DfSAY9oh/ieNd4RYKOrlxSQbWkZleCTwNVXz6QTvIPa GatmAdvemneCVmLok6d/SownaSHSeoFUZ/56PZCIOFxE2rulneK1j9koNYFgaeWx1ny9 goBo38+gsgoPVgiXUJactKWTa89ILY49QinKaf+uJbv2fCkb9/l8fXm6tykLL9P/OGfn iTvy75Ea6Wx2jOZijSvcR4RujWSY10QfSUa7XlUDXUoQqvtqrX/TJEWl+MbWeH6D1DLx H5KA== X-Gm-Message-State: AOAM530+XSbtN9WRBYZoGFYx4/rSXdPJSyQ3xHpiUROyM9P+GDmsKTQ4 uYu/O1dwtf9yoiESSGT5ORr+zElolN67QaKahDb+Kg== X-Google-Smtp-Source: ABdhPJwwgYm9gSe18/JyjErLTRz5FCOkyXxd4stR4ZaLz//fROhqjDQGN2y2rtdVkMLB3bpoDtl1Y3uYT/scb2Xt5zw= X-Received: by 2002:a05:6902:1025:: with SMTP id x5mr2865453ybt.96.1612947330653; Wed, 10 Feb 2021 00:55:30 -0800 (PST) MIME-Version: 1.0 References: <20210205222644.2357303-1-saravanak@google.com> <47ca46aa-99f3-5203-8aa7-65c6443bd965@microchip.com> In-Reply-To: <47ca46aa-99f3-5203-8aa7-65c6443bd965@microchip.com> From: Saravana Kannan Date: Wed, 10 Feb 2021 00:54:54 -0800 Message-ID: Subject: Re: [PATCH v4 0/8] Make fw_devlink=on more forgiving To: Tudor Ambarus Cc: Jonathan Corbet , Greg Kroah-Hartman , "Rafael J. Wysocki" , Kevin Hilman , Ulf Hansson , "Brown, Len" , Len Brown , Pavel Machek , Michael Turquette , Stephen Boyd , Rob Herring , Frank Rowand , Marc Zyngier , Thomas Gleixner , Linux Doc Mailing List , LKML , Linux PM , linux-clk , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , ACPI Devel Maling List , Marek Szyprowski , Geert Uytterhoeven , Android Kernel Team Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Wed, Feb 10, 2021 at 12:19 AM wrote: > > Hi, Saravana, > > On 2/6/21 12:26 AM, Saravana Kannan wrote: > > There are a lot of devices/drivers where they never have a struct device > > created for them or the driver initializes the hardware without ever > > binding to the struct device. > > > > This series is intended to avoid any boot regressions due to such > > devices/drivers when fw_devlink=on and also address the handling of > > optional suppliers. > > > > Patch 1 and 2 addresses the issue of firmware nodes that look like > > they'll have struct devices created for them, but will never actually > > have struct devices added for them. For example, DT nodes with a > > compatible property that don't have devices added for them. > > > > Patch 3 and 4 allow for handling optional DT bindings. > > > > Patch 5 sets up a generic API to handle drivers that never bind with > > their devices. > > > > Patch 6 through 8 update different frameworks to use the new API. > > > > Thanks, > > Saravana > > > > Saravana Kannan (8): > > driver core: fw_devlink: Detect supplier devices that will never be > > added > > of: property: Don't add links to absent suppliers > > driver core: Add fw_devlink.strict kernel param > > of: property: Add fw_devlink support for optional properties > > driver core: fw_devlink: Handle suppliers that don't use driver core > > irqdomain: Mark fwnodes when their irqdomain is added/removed > > PM: domains: Mark fwnodes when their powerdomain is added/removed > > clk: Mark fwnodes when their clock provider is added/removed > > > > .../admin-guide/kernel-parameters.txt | 5 ++ > > drivers/base/core.c | 58 ++++++++++++++++++- > > drivers/base/power/domain.c | 2 + > > drivers/clk/clk.c | 3 + > > drivers/of/property.c | 16 +++-- > > include/linux/fwnode.h | 20 ++++++- > > kernel/irq/irqdomain.c | 2 + > > 7 files changed, 98 insertions(+), 8 deletions(-) > > > > Even with this patch set applied, sama5d2_xplained can not boot. > Patch at [1] makes sama5d2_xplained boot again. Stephen applied it > to clk-next. I'm glad you won't actually have any boot issues in 5.12, but the fact you need [1] with this series doesn't make a lot of sense to me because: 1. The FWNODE_FLAG_INITIALIZED flag will be set for the clock fwnode in question way before any consumer devices are added. 2. Any consumer device added after (1) will stop trying to link to the clock device. Are you somehow adding a consumer to the clock fwnode before (1)? Can you try this patch without your clk fix? I was trying to avoid looping through a list, but looks like your case might somehow need it? -Saravana +++ b/drivers/base/core.c @@ -943,6 +943,31 @@ static void device_links_missing_supplier(struct device *dev) } } +static int fw_devlink_check_suppliers(struct device *dev) +{ + struct fwnode_link *link; + int ret = 0; + + if (!dev->fwnode ||fw_devlink_is_permissive()) + return 0; + + /* + * Device waiting for supplier to become available is not allowed to + * probe. + */ + mutex_lock(&fwnode_link_lock); + list_for_each_entry(link, &dev->fwnode->suppliers, c_hook) { + if (link->supplier->flags & FWNODE_FLAG_INITIALIZED) + continue; + + ret = -EPROBE_DEFER; + break; + } + mutex_unlock(&fwnode_link_lock); + + return ret; +} + /** * device_links_check_suppliers - Check presence of supplier drivers. * @dev: Consumer device. @@ -964,21 +989,13 @@ int device_links_check_suppliers(struct device *dev) struct device_link *link; int ret = 0; - /* - * Device waiting for supplier to become available is not allowed to - * probe. - */ - mutex_lock(&fwnode_link_lock); - if (dev->fwnode && !list_empty(&dev->fwnode->suppliers) && - !fw_devlink_is_permissive()) { + if (fw_devlink_check_suppliers(dev)) { dev_dbg(dev, "probe deferral - wait for supplier %pfwP\n", list_first_entry(&dev->fwnode->suppliers, struct fwnode_link, c_hook)->supplier); - mutex_unlock(&fwnode_link_lock); return -EPROBE_DEFER; } - mutex_unlock(&fwnode_link_lock); device_links_write_lock(); > > Cheers, > ta > > [1] https://lore.kernel.org/lkml/20210203154332.470587-1-tudor.ambarus@microchip.com/