Re: [PATCH v3 3/3] ARM: at91: remove unnecessary of_platform_default_populate calls

[Alexander Dahl <ada@thorsis.com>]

Hello Miquel,

Am Wed, Apr 29, 2026 at 11:42:19AM +0200 schrieb Miquel Raynal:
> Hi Alexander,
> 
> >     [    0.958298] bus: 'platform': add driver atmel-ebi
> >     [    0.958451] platform 10000000.ebi: bus: 'platform': __driver_probe_device: matched device with driver atmel-ebi
> >     [    0.958566] platform 10000000.ebi: error -EPROBE_DEFER: wait for supplier /ahb/apb/pinctrl@fffff400/ebi/ebi-data-lsb
> >     [    0.958649] platform 10000000.ebi: Added to deferred list
> >     [    0.959429] bus: 'platform': remove driver atmel-ebi
> >     [    0.959540] driver: 'atmel-ebi': driver_release
> 
> Interesting.
> 
> If you look at the very last line of the driver, the EBI driver does not
> use a standard "module_platform_driver" macro, it uses some kind of
> run-once probe that is kept in an __init section:
> https://elixir.bootlin.com/linux/v7.0.1/source/drivers/memory/atmel-ebi.c#L637
> 
> And this seems to be incompatible with probe deferrals:
> https://elixir.bootlin.com/linux/v7.0.1/source/drivers/base/platform.c#L948

Indeed. o.O

> I would suggest trying something alone these lines:
> 
> --- a/drivers/memory/atmel-ebi.c
> +++ b/drivers/memory/atmel-ebi.c
> @@ -633,5 +633,6 @@ static struct platform_driver atmel_ebi_driver = {
>                 .of_match_table = atmel_ebi_id_table,
>                 .pm = &atmel_ebi_pm_ops,
>         },
> +       .probe = atmel_ebi_probe,
>  };
> -builtin_platform_driver_probe(atmel_ebi_driver, atmel_ebi_probe);
> +builtin_platform_driver(atmel_ebi_driver);
> 
> Memory taken by the probe function will remain mapped. That seems to be
> the drawback.

This works.  Sent a patch, see:

https://lore.kernel.org/all/20260429125930.844790-1-ada@thorsis.com/

Regarding the drawback: This can't be much memory, can it?

Greets
Alex