linux-kernel - Re: [PATCH 2/3] clocksource/drivers/nxp-pit: Prevent driver unbind

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Message-ID: <aRRpFWfgz0OYpdWy@hovoldconsulting.com>
Date: Wed, 12 Nov 2025 12:01:41 +0100
From: Johan Hovold <johan@...nel.org>
To: Daniel Lezcano <daniel.lezcano@...aro.org>
Cc: Mark Rutland <mark.rutland@....com>, Marc Zyngier <maz@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/3] clocksource/drivers/nxp-pit: Prevent driver unbind

On Wed, Nov 12, 2025 at 11:00:05AM +0100, Daniel Lezcano wrote:
> On 11/11/25 16:32, Johan Hovold wrote:
> > The driver does not support unbinding (e.g. as clockevents cannot be
> > deregistered) so suppress the bind attributes to prevent the driver from
> > being unbound and rebound after registration (and disabling the timer
> > when reprobing fails).
> > 
> > Even if the driver can currently only be built-in, also switch to
> > builtin_platform_driver() to prevent it from being unloaded should
> > modular builds ever be enabled.
> > 
> > Fixes: bee33f22d7c3 ("clocksource/drivers/nxp-pit: Add NXP Automotive s32g2 / s32g3 support")
> > Signed-off-by: Johan Hovold <johan@...nel.org>
> > ---
> >   drivers/clocksource/timer-nxp-pit.c | 3 ++-
> >   1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/clocksource/timer-nxp-pit.c b/drivers/clocksource/timer-nxp-pit.c
> > index 2d0a3554b6bf..d1740f18f718 100644
> > --- a/drivers/clocksource/timer-nxp-pit.c
> > +++ b/drivers/clocksource/timer-nxp-pit.c
> > @@ -374,9 +374,10 @@ static struct platform_driver nxp_pit_driver = {
> >   	.driver = {
> >   		.name = "nxp-pit",
> >   		.of_match_table = pit_timer_of_match,
> > +		.suppress_bind_attrs = true,
> >   	},
> >   	.probe = pit_timer_probe,
> >   };
> > -module_platform_driver(nxp_pit_driver);
> > +builtin_platform_driver(nxp_pit_driver);
> 
> Do not use builtin_platform here. You can add the tristate Kconfig 
> option for this driver, I tested it.

As I just commented on the cover letter, that's not relevant here;
builtin_platform_driver() only prevents unloading a driver built as a
module (which is something we want to prevent for these drivers).

Johan