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References: <20210216123958.3180014-1-geert+renesas@glider.be>
In-Reply-To: <20210216123958.3180014-1-geert+renesas@glider.be>
From:   Saravana Kannan <saravanak@google.com>
Date:   Tue, 16 Feb 2021 10:25:59 -0800
Message-ID: <CAGETcx_YeiNAMkSxtbTSZcsQugxK4=CwhR6UfbSLLHzQ2EfguA@mail.gmail.com>
Subject: Re: [PATCH v2] soc: renesas: rmobile-sysc: Mark fwnode when PM domain
 is added
To:     Geert Uytterhoeven <geert+renesas@glider.be>
Cc:     Magnus Damm <magnus.damm@gmail.com>,
        Sebastian Reichel <sre@kernel.org>,
        Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        Linux PM <linux-pm@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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On Tue, Feb 16, 2021 at 4:40 AM Geert Uytterhoeven
<geert+renesas@glider.be> wrote:
>
> Currently, there are two drivers binding to the R-Mobile System
> Controller (SYSC):
>   - The rmobile-sysc driver registers PM domains from a core_initcall(),
>     and does not use a platform driver,
>   - The optional rmobile-reset driver registers a reset handler, and
>     does use a platform driver.
>
> As fw_devlink only considers devices, commit bab2d712eeaf9d60 ("PM:
> domains: Mark fwnodes when their powerdomain is added/removed") works
> only for PM Domain drivers where the DT node is a real device node, and
> not for PM Domain drivers using a hierarchical representation inside a
> subnode.  Hence if fw_devlink is enabled, probing of on-chip devices
> that are part of the SYSC PM domain is deferred until the optional
> rmobile-reset driver has been bound.   If the rmobile-reset driver is
> not available, this will never happen, and thus lead to complete system
> boot failures.
>
> Fix this by explicitly marking the fwnode initialized.
>
> Suggested-by: Saravana Kannan <saravanak@google.com>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
> This is v2 of "soc: renesas: rmobile-sysc: Set OF_POPULATED and absorb
> reset handling".
> To be queued in renesas-devel as a fix for v5.12 if v5.12-rc1 will have
> fw_devlink enabled.
>
> v2:
>   - Call fwnode_dev_initialized() instead of setting OF_POPULATED,
>   - Drop reset handling move, as fwnode_dev_initialized() does not
>     prevent the rmobile-reset driver from binding against the same
>     device.
> ---
>  drivers/soc/renesas/rmobile-sysc.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/soc/renesas/rmobile-sysc.c b/drivers/soc/renesas/rmobile-sysc.c
> index bf64d052f9245db5..204e6135180b919c 100644
> --- a/drivers/soc/renesas/rmobile-sysc.c
> +++ b/drivers/soc/renesas/rmobile-sysc.c
> @@ -342,6 +342,8 @@ static int __init rmobile_init_pm_domains(void)
>                         of_node_put(np);
>                         break;
>                 }
> +
> +               fwnode_dev_initialized(&np->fwnode, true);
>         }
>
>         put_special_pds();

Acked-by: Saravana Kannan <saravanak@google.com>

Keep in mind that this might have to land in driver-core-next since
that API is currently only in driver-core-next.

-Saravana