linux-kernel - Re: [PATCH v4 4/6] driver core: Remove driver_deferred_probe_check_state

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Date:   Thu, 20 Feb 2020 11:38:30 +0100
From:   "Rafael J. Wysocki" <rafael@...nel.org>
To:     John Stultz <john.stultz@...aro.org>
Cc:     lkml <linux-kernel@...r.kernel.org>, Rob Herring <robh@...nel.org>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Kevin Hilman <khilman@...nel.org>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Pavel Machek <pavel@....cz>, Len Brown <len.brown@...el.com>,
        Todd Kjos <tkjos@...gle.com>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>,
        Thierry Reding <treding@...dia.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Linux PM <linux-pm@...r.kernel.org>
Subject: Re: [PATCH v4 4/6] driver core: Remove driver_deferred_probe_check_state_continue()

On Thu, Feb 20, 2020 at 6:05 AM John Stultz <john.stultz@...aro.org> wrote:
>
> Now that driver_deferred_probe_check_state() works better, and
> we've converted the only user of
> driver_deferred_probe_check_state_continue() we can simply
> remove it and simplify some of the logic.
>
> Cc: Rob Herring <robh@...nel.org>
> Cc: "Rafael J. Wysocki" <rjw@...ysocki.net>
> Cc: Kevin Hilman <khilman@...nel.org>
> Cc: Ulf Hansson <ulf.hansson@...aro.org>
> Cc: Pavel Machek <pavel@....cz>
> Cc: Len Brown <len.brown@...el.com>
> Cc: Todd Kjos <tkjos@...gle.com>
> Cc: Bjorn Andersson <bjorn.andersson@...aro.org>
> Cc: Liam Girdwood <lgirdwood@...il.com>
> Cc: Mark Brown <broonie@...nel.org>
> Cc: Thierry Reding <treding@...dia.com>
> Cc: Linus Walleij <linus.walleij@...aro.org>
> Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
> Cc: linux-pm@...r.kernel.org
> Signed-off-by: John Stultz <john.stultz@...aro.org>
> Change-Id: Id5cd5e9264cfb0fbd70a702715174cc4b10006f4

Nice!

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

> ---
>  drivers/base/dd.c             | 49 +++++------------------------------
>  include/linux/device/driver.h |  1 -
>  2 files changed, 6 insertions(+), 44 deletions(-)
>
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index fa138f24e2d3..408e4da081da 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -244,19 +244,6 @@ static int __init deferred_probe_timeout_setup(char *str)
>  }
>  __setup("deferred_probe_timeout=", deferred_probe_timeout_setup);
>
> -static int __driver_deferred_probe_check_state(struct device *dev)
> -{
> -       if (!initcalls_done || deferred_probe_timeout > 0)
> -               return -EPROBE_DEFER;
> -
> -       if (!deferred_probe_timeout) {
> -               dev_WARN(dev, "deferred probe timeout, ignoring dependency");
> -               return -ETIMEDOUT;
> -       }
> -
> -       return 0;
> -}
> -
>  /**
>   * driver_deferred_probe_check_state() - Check deferred probe state
>   * @dev: device to check
> @@ -272,43 +259,19 @@ static int __driver_deferred_probe_check_state(struct device *dev)
>   */
>  int driver_deferred_probe_check_state(struct device *dev)
>  {
> -       int ret;
> +       if (!initcalls_done || deferred_probe_timeout > 0)
> +               return -EPROBE_DEFER;
>
> -       ret = __driver_deferred_probe_check_state(dev);
> -       if (ret < 0)
> -               return ret;
> +       if (!deferred_probe_timeout) {
> +               dev_WARN(dev, "deferred probe timeout, ignoring dependency");
> +               return -ETIMEDOUT;
> +       }
>
>         dev_warn(dev, "ignoring dependency for device, assuming no driver");
>
>         return -ENODEV;
>  }
>
> -/**
> - * driver_deferred_probe_check_state_continue() - check deferred probe state
> - * @dev: device to check
> - *
> - * Returns -ETIMEDOUT if deferred probe debug timeout has expired, or
> - * -EPROBE_DEFER otherwise.
> - *
> - * Drivers or subsystems can opt-in to calling this function instead of
> - * directly returning -EPROBE_DEFER.
> - *
> - * This is similar to driver_deferred_probe_check_state(), but it allows the
> - * subsystem to keep deferring probe after built-in drivers have had a chance
> - * to probe. One scenario where that is useful is if built-in drivers rely on
> - * resources that are provided by modular drivers.
> - */
> -int driver_deferred_probe_check_state_continue(struct device *dev)
> -{
> -       int ret;
> -
> -       ret = __driver_deferred_probe_check_state(dev);
> -       if (ret < 0)
> -               return ret;
> -
> -       return -EPROBE_DEFER;
> -}
> -
>  static void deferred_probe_timeout_work_func(struct work_struct *work)
>  {
>         struct device_private *private, *p;
> diff --git a/include/linux/device/driver.h b/include/linux/device/driver.h
> index 1188260f9a02..5242afabfaba 100644
> --- a/include/linux/device/driver.h
> +++ b/include/linux/device/driver.h
> @@ -238,7 +238,6 @@ driver_find_device_by_acpi_dev(struct device_driver *drv, const void *adev)
>
>  void driver_deferred_probe_add(struct device *dev);
>  int driver_deferred_probe_check_state(struct device *dev);
> -int driver_deferred_probe_check_state_continue(struct device *dev);
>  void driver_init(void);
>
>  /**
> --