Re: [PATCH v4 1/4] kernel: param: initialize module_kset before do_initcalls()

[Jon Hunter]

Hi Shashank,

On 12/05/2026 03:12, Shashank Balaji wrote:

...

> > Hi Thierry and Jonathan,
> >
> > You can find the context for this email in this patch:
> > https://lore.kernel.org/all/20260427-acpi_mod_name-v4-1-22b42240c9bf@xxxxxxxx/
> >
> > TL;DR: tegra194_cbb_driver and tegra234_cbb_driver are the only drivers
> > registering themselves as early as in a pure_initcall. This is a problem
> > on two fronts:
> > 1. Philosophical: As Gary pointed out, pure_initcalls are intended to purely
> > initialize variables that couldn't be statically initialized. But these
> > are doing driver registrations.
> > 2. module_kset not initialized at pure_initcall stage: This is needed to
> > set the module sysfs symlink. Since module_kset is not alive yet during
> > pure_initcalls, registering these drivers panics the kernel.

Where exactly is this panic seen? Ie. why are we not seeing this?

> > We would like to do the tegra cbb driver registration in a core_initcall
> > (or some later initcall works too), and move module_kset initialization
> > to a pure_initcall. Like this:
> >
> > diff --git a/drivers/soc/tegra/cbb/tegra194-cbb.c b/drivers/soc/tegra/cbb/tegra194-cbb.c
> > index ab75d50cc85c..2f69e104c838 100644
> > --- a/drivers/soc/tegra/cbb/tegra194-cbb.c
> > +++ b/drivers/soc/tegra/cbb/tegra194-cbb.c
> > @@ -2342,7 +2342,7 @@ static int __init tegra194_cbb_init(void)
> >   {
> >          return platform_driver_register(&tegra194_cbb_driver);
> >   }
> > -pure_initcall(tegra194_cbb_init);
> > +core_initcall(tegra194_cbb_init);
> >
> >   static void __exit tegra194_cbb_exit(void)
> >   {
> > diff --git a/drivers/soc/tegra/cbb/tegra234-cbb.c b/drivers/soc/tegra/cbb/tegra234-cbb.c
> > index fb26f085f691..785072fa4e85 100644
> > --- a/drivers/soc/tegra/cbb/tegra234-cbb.c
> > +++ b/drivers/soc/tegra/cbb/tegra234-cbb.c
> > @@ -1774,7 +1774,7 @@ static int __init tegra234_cbb_init(void)
> >   {
> >          return platform_driver_register(&tegra234_cbb_driver);
> >   }
> > -pure_initcall(tegra234_cbb_init);
> > +core_initcall(tegra234_cbb_init);
> >
> >   static void __exit tegra234_cbb_exit(void)
> >   {
> >
> > Would this work?


I am adding Sumit who has been doing a lot of the Tegra CBB driver work.

Sumit, any concerns here? We could run this change through our internal 
testing to confirm.

Jon

--
nvpublic