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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0215C433FE for ; Tue, 5 Oct 2021 15:07:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 93E26613D5 for ; Tue, 5 Oct 2021 15:07:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235651AbhJEPJE (ORCPT ); Tue, 5 Oct 2021 11:09:04 -0400 Received: from mail-ua1-f54.google.com ([209.85.222.54]:37726 "EHLO mail-ua1-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229488AbhJEPJD (ORCPT ); Tue, 5 Oct 2021 11:09:03 -0400 Received: by mail-ua1-f54.google.com with SMTP id i13so443927uat.4; Tue, 05 Oct 2021 08:07:12 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=bk0G/z1T/uosdH3nhuVAPRarw22NSmvJmajc0ie3v6A=; b=bN53d8riJpjCyaARGHXvJW88vILTqKU2VwG8/fdJRTH3rxfwBDBC32In8GohAuiuxr g4vsVsfAg3ijBNWs9Rq5rhdG3dR17TrkNqKHgd0dQ6pszTElkcV6XTQxNVzUUWJ8A1iN foWlfYHv/IdvJ7xTAqCX6RyompmmI6ssO6kx0u7N1SSz+qT825wm/I3IGPntixoGl5dl LTEkfTQOPux2us0cnZquNpItbX8GnRibsgDSGw+r4RgXGM1BQu3d6VY8yWk234dzK+9s sfiMrKCQBOLaOzz+feZwOOIK3HYyNTjRfA7ok49yj3aa2ZyEKqd8d9wEBhn9/OuxEAic aCkw== X-Gm-Message-State: AOAM531sPTEydhQrq6Fv6S/l6dg8W5uzGA49w//lnn4VAiyvZm1bqaS4 Kk/nQB26YU+O4oem5Gkh7RmBM8I+hPt9Wy3pnhc= X-Google-Smtp-Source: ABdhPJzxRXB84hERP6o6WD8zVyYzPaZTAX750wbPz4I9CTy02fziulaptkej0GIkEyJDLO2QdDkhEc1GsBZ/isZxSXk= X-Received: by 2002:ab0:538a:: with SMTP id k10mr13022243uaa.14.1633446432404; Tue, 05 Oct 2021 08:07:12 -0700 (PDT) MIME-Version: 1.0 References: <20210929000735.585237-1-saravanak@google.com> <20210929000735.585237-2-saravanak@google.com> In-Reply-To: <20210929000735.585237-2-saravanak@google.com> From: Geert Uytterhoeven Date: Tue, 5 Oct 2021 17:07:01 +0200 Message-ID: Subject: Re: [PATCH v4 1/2] drivers: bus: simple-pm-bus: Add support for probing simple bus only devices To: Saravana Kannan Cc: Russell King , Neil Armstrong , Magnus Damm , Tony Lindgren , Catalin Marinas , Will Deacon , Damien Le Moal , Greg Kroah-Hartman , Ulf Hansson , Rob Herring , Android Kernel Team , Linux ARM , Linux Kernel Mailing List , linux-oxnas@groups.io, Linux-Renesas , "open list:TI ETHERNET SWITCH DRIVER (CPSW)" , linux-riscv Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 29, 2021 at 2:07 AM 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, probe these > devices using the simple-pm-bus driver. > > However, there are instances of devices that are not simple buses (they get > probed by their specific drivers) that also list the "simple-bus" (or other > bus only compatible strings) in their compatible property to automatically > populate their child devices. We still want these devices to get probed by > their specific drivers. So, we make sure this driver only probes devices > that are only buses. > > [1] - https://lore.kernel.org/lkml/CAPDyKFo9Bxremkb1dDrr4OcXSpE0keVze94Cm=zrkOVxHHxBmQ@mail.gmail.com/ > Fixes: c442a0d18744 ("driver core: Set fw_devlink to "permissive" behavior by default") > Signed-off-by: Saravana Kannan > Tested-by: Saravana Kannan > Tested-by: Ulf Hansson Works fine on R-Car Gen/Gen3 (simple-bus), and SH-Mobile AG5 and R-Mobile APE6 (simple-pm-bus). Tested-by: Geert Uytterhoeven Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds