Re: [PATCH 02/13] ARM: remove footbridge

["Arnd Bergmann" <arnd@kernel.org>]

On Tue, Sep 8, 2026, at 17:55, sashiko-bot@kernel.org wrote:
>>  __tagtable(ATAG_MEM, parse_tag_mem32);
>>  
>> -#if defined(CONFIG_ARCH_FOOTBRIDGE) && defined(CONFIG_VGA_CONSOLE)
>> -static int __init parse_tag_videotext(const struct tag *tag)
>> -{
> [ ... ]
>> -__tagtable(ATAG_VIDEOTEXT, parse_tag_videotext);
>> -#endif
>> -
>
> [Severity: Medium]
> Since this patch removes the footbridge architecture, should similar
> arch-specific dead code be removed from arch/arm/kernel/atags_compat.c as
> well?

I have a separate patch to remove that file entirely and chose
not to remove the lines here to avoid a merge conflict.

>> deleted file mode 100644
>> index 96a74d447028d..0000000000000
>> --- a/arch/arm/mach-footbridge/Kconfig
>> +++ /dev/null
>> @@ -1,57 +0,0 @@
> [ ... ]
>> -config ARCH_NETWINDER
>> -	bool "NetWinder"
> [ ... ]
>> -config FOOTBRIDGE
>> -	def_bool y
>
> [Severity: Medium]
> By removing the FOOTBRIDGE and ARCH_NETWINDER configs here, what happens to
> the drivers in other subsystems that still depend on them? 
>
> For example, drivers/watchdog/Kconfig still contains dependencies like:
>     config 21285_WATCHDOG
>         depends on FOOTBRIDGE

See the longer series with the patches to remove this.

> And drivers/char/Kconfig has symbols like DS1620, NWBUTTON, and NWFLASH
> that depend on ARCH_NETWINDER. Will these be left permanently unbuildable
> since their configurations are orphaned?
>
> Additionally, 977_WATCHDOG depends on:
>     (FOOTBRIDGE && ARCH_NETWINDER) || (ARM && COMPILE_TEST)
>
> If someone builds with COMPILE_TEST, won't this driver try to build but
> fail due to missing headers?

I don't see any headers causing problems in 977_WATCHDOG, but
I'll do some more build testing on the current series before
I post the next version.

I did randconfig tests on a slightly older version of the longer
series, but not on intermediate parts, so it's possible that
I missed something there.

>> diff --git a/arch/arm/include/asm/hardware/dec21285.h b/arch/arm/include/asm/hardware/dec21285.h
>> deleted file mode 100644
>> index 894f2a635cbbd..0000000000000
>> --- a/arch/arm/include/asm/hardware/dec21285.h
>> +++ /dev/null
>
> [Severity: Medium]
> Will the removal of this header cause fatal build errors for the orphaned
> drivers mentioned above?
>
> For example, if compilation is attempted (such as with COMPILE_TEST),
> nwflash_init() in drivers/char/nwflash.c and serial21285_init() in 
> drivers/tty/serial/21285.c both still include <asm/hardware/dec21285.h>.
>
> Does this patch need to remove those orphaned drivers as well to prevent
> build breakages?

The nwflash/nwbutton and dc21285_serial drivers have a hard
dependency on ARCH_NETWINDER, so those should be fine.

       Arnd