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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Fri, 27 Apr 2018 17:13:20 +0200
Message-ID: <CAK8P3a13wiATdYDGXnmEMfpoKzXqWA-umKLgO7hFaJj3MF4w1Q@mail.gmail.com>
Subject: Re: [PATCH RFC PoC 1/2] earlydev: implement a new way to probe
 platform devices early
To:     Bartosz Golaszewski <brgl@bgdev.pl>
Cc:     Sekhar Nori <nsekhar@ti.com>, Kevin Hilman <khilman@kernel.org>,
        David Lechner <david@lechnology.com>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Yoshinori Sato <ysato@users.sourceforge.jp>,
        Rich Felker <dalias@libc.org>,
        Frank Rowand <frowand.list@gmail.com>,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Arend van Spriel <aspriel@gmail.com>,
        Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        Michal Suchanek <msuchanek@suse.de>,
        Jan Kiszka <jan.kiszka@siemens.com>,
        Andy Shevchenko <andy.shevchenko@gmail.com>,
        Marc Zyngier <marc.zyngier@arm.com>,
        Peter Rosin <peda@axentia.se>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        DTML <devicetree@vger.kernel.org>,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>
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On Thu, Apr 26, 2018 at 5:29 PM, Bartosz Golaszewski <brgl@bgdev.pl> wrote:

> +/*
> + * REVISIT: early_initcall may be still too late for some timers and critical
> + * clocks. We should probably have a separate section with callbacks that can
> + * be invoked at each architecture's discretion.
> + */
> +#define earlydev_platform_driver(_drv)                                 \
> +       static int _drv##_register(void)                                \
> +       {                                                               \
> +               earlydev_driver_register(&(_drv));                      \
> +               return 0;                                               \
> +       }                                                               \
> +       early_initcall(_drv##_register)
> +
> +#endif /* __EARLYDEV_H__ */

No full review, just one comment: this would really need to fit into the
existing callbacks for clk, timer, earlycon etc that we use with OF_DECLARE.
A lot of code makes assumptions about the order in which they are
called, and the current early_platform infrastructure does the same
thing using its "earlyprintk" and "earlytimer" classes.

       Arnd