Re: [PATCH] clk: imx8mp: register driver at arch_initcall time

From: Fabio Estevam <festevam@gmail.com>
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Abel Vesa <abelvesa@kernel.org>,
	Michael Turquette <mturquette@baylibre.com>,
	Stephen Boyd <sboyd@kernel.org>, Shawn Guo <shawnguo@kernel.org>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	NXP Linux Team <linux-imx@nxp.com>,
	linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org
Subject: Re: [PATCH] clk: imx8mp: register driver at arch_initcall time
Date: Sat, 19 Nov 2022 18:38:53 -0300	[thread overview]
Message-ID: <CAOMZO5BPtEU6VCZXRk5FTHXDad6cegF=+oHTTA0wgjBuoh9-rQ@mail.gmail.com> (raw)
In-Reply-To: <20220928124108.500369-1-linux@rasmusvillemoes.dk>

On Wed, Sep 28, 2022 at 9:41 AM Rasmus Villemoes
<linux@rasmusvillemoes.dk> wrote:
>
> We have an imx8mp-based board with an external gpio-triggered
> watchdog. Currently, we don't get to handle that in time before it
> resets the board.
>
> The probe of the watchdog device gets deferred because the SOC's GPIO
> controller is not yet ready, and the probe of that in turn gets deferred
> because its clock provider (namely, this driver) is not yet
> ready. Altogether, the watchdog does not get handled until the late
> initcall deferred_probe_initcall has made sure all leftover devices
> have been probed, and that's way too late.
>
> Aside from being necessary for our board, this also reduces total boot
> time because fewer device probes get deferred.
>
> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
> ---
> It would probably be reasonable to do the same to the other imx8m* clk
> drivers, but I don't have any such hardware to test on.

Agreed.

> +static void __exit imx8mp_clk_exit(void)
> +{
> +       platform_driver_unregister(&imx8mp_clk_driver);
> +}
> +module_exit(imx8mp_clk_exit);

Isn't module_exit() unnecessary here, since we pass suppress_bind_attrs = true?

With module_exit() removed:

Reviewed-by: Fabio Estevam <festevam@gmail.com>