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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 0AF8AC433F5 for ; Tue, 7 Sep 2021 10:36:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E1F3F610C8 for ; Tue, 7 Sep 2021 10:36:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245429AbhIGKhf (ORCPT ); Tue, 7 Sep 2021 06:37:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45976 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245368AbhIGKhe (ORCPT ); Tue, 7 Sep 2021 06:37:34 -0400 Received: from mail-lf1-x129.google.com (mail-lf1-x129.google.com [IPv6:2a00:1450:4864:20::129]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 90D09C061575 for ; Tue, 7 Sep 2021 03:36:28 -0700 (PDT) Received: by mail-lf1-x129.google.com with SMTP id y34so18584678lfa.8 for ; Tue, 07 Sep 2021 03:36:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=39dcuRpzaRC5BdwM3JqFxL9Y6Q3cQwXZto24BgL4zlw=; b=WRPwsUgs3jtAT985APtpAk7gOLDCyjfqConNDw11zz00sChZxuthXUGYMXMobYeT6M VpMPeE4+aAP/7PFEWpW8s+uoC+BF2cF4tOVrebQAFyWaqHmG/IjgTepK4IvgA1kWTTsK hLK98/P7/EVpFMY5VCM+9gimM1MGCgUGuxyXCA+3xG+tMKIiCN55tbN3z2gSRJRJ8XJC D618HhXkEfoa+AtVON0zbllCFLG0x6/yVkz9U9zEDrPn+ccRk7scvDsHcMvp3/DG3UYc iHUdVdX9poEASUwIJqZpv672VVlyEyVGetdOZiLhAnFOYkDaApJKquA3w6M4FtPs8yxE tcQw== 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=39dcuRpzaRC5BdwM3JqFxL9Y6Q3cQwXZto24BgL4zlw=; b=ox0wrxSfiuhSp67XYHERGE959GlyjtQhmVBz10Cnbl8Q41a3SwC3XQN9SsG+VT3LeP 3phcDIPYMVhpkLRE7ODvjhxy7BsWeMHr8tMVW0bkDjV0aQwxZV+prjdErUhWyvGSYdyE XM1zl57Yc587Tm1oAAUu8c3CmQbp8DfYCbwjyZxv16Van5Jc2dCb3YjEsk5Lqv+PXCzo E51FXN9DtM02jQlfVhenUiVLcFdEL7ndro5kJY1xIN9VxrlSDjKoZmCKKOTM1kee8Yww g4chhfxFaqmO6yeswBA19eBe18CZ3F4WnKPyj34IM6yA6C/AnOxIWl2TRXCGiVgdt7d2 4X8A== X-Gm-Message-State: AOAM532hkWDU9mQ8BJu2gqIWZcyYbNWzN3Oo2clF5TBljO6ggNJrKu2V CVrO93X0uuS0CMuneF3LBXsPRbkrdgfXpKCjquHdQMzBvNw= X-Google-Smtp-Source: ABdhPJwwA0NSPTO/J8/Y+LSVPXUrJzOZ6ZFh4DSu0zI1UQW0yIXFDmNMkzM2NaFOX+3m36whk5wogBMs2rmww/YsDKo= X-Received: by 2002:a05:6512:1528:: with SMTP id bq40mr1777835lfb.71.1631010986959; Tue, 07 Sep 2021 03:36:26 -0700 (PDT) MIME-Version: 1.0 References: <20210902230442.1515531-1-saravanak@google.com> <20210902230442.1515531-2-saravanak@google.com> In-Reply-To: From: Ulf Hansson Date: Tue, 7 Sep 2021 12:35:50 +0200 Message-ID: Subject: Re: [PATCH v2 1/2] of: platform: Make sure bus only devices get probed To: Geert Uytterhoeven Cc: Saravana Kannan , Rob Herring , Frank Rowand , Android Kernel Team , Linux Kernel Mailing List , DTML Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Fri, 3 Sept 2021 at 16:29, Geert Uytterhoeven wrote: > > Hi Ulf, > > On Fri, Sep 3, 2021 at 11:19 AM Ulf Hansson wrote: > > On Fri, 3 Sept 2021 at 01:04, Saravana Kannan wrote: > > > fw_devlink could end up creating device links for bus only devices. > > > However, bus only devices don't get probed and can block probe() or > > > sync_state() [1] call backs of other devices. To avoid this, set up > > > these devices to get probed by the simple-pm-bus. > > > > > > [1] - https://lore.kernel.org/lkml/CAPDyKFo9Bxremkb1dDrr4OcXSpE0keVze94Cm=zrkOVxHHxBmQ@mail.gmail.com/ > > > Signed-off-by: Saravana Kannan > > > Tested-by: Saravana Kannan > > > > Again, this looks like a nice solution to the problem. > > > > One question though. The Kconfig SIMPLE_PM_BUS, should probably be > > "default y" - or something along those lines to make sure fw_devlink > > works as expected. > > I would love for SIMPLE_PM_BUS to go away, and all of its functionality > to be usurped by the standard simple-bus handling. > > In the modern world, everything uses power management and Runtime > PM, and the distinction between "simple-bus" and "simple-pm-bus" > is purely artificial. I think it's not that easy, but maybe I am wrong. Today we have an opt-in way of supporting runtime PM (and power management). In most cases it's up to drivers or subsystem level code to decide if runtime PM should be enabled for the device. Would it really be okay to enable runtime PM for all of them? Kind regards Uffe