Re: [PATCH 06/12] arch: Declare screen_info in <asm/screen_info.h>

Hi

Am 29.06.23 um 15:03 schrieb Arnd Bergmann:
> On Thu, Jun 29, 2023, at 13:45, Thomas Zimmermann wrote:
> 
>> diff --git a/include/asm-generic/screen_info.h
>> b/include/asm-generic/screen_info.h
>> new file mode 100644
>> index 0000000000000..6fd0e50fabfcd
>> --- /dev/null
>> +++ b/include/asm-generic/screen_info.h
>> @@ -0,0 +1,12 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +
>> +#ifndef _ASM_GENERIC_SCREEN_INFO_H
>> +#define _ASM_GENERIC_SCREEN_INFO_H
>> +
>> +#include <uapi/linux/screen_info.h>
>> +
>> +#if defined(CONFIG_ARCH_HAS_SCREEN_INFO)
>> +extern struct screen_info screen_info;
>> +#endif
>> +
>> +#endif /* _ASM_GENERIC_SCREEN_INFO_H */
>> diff --git a/include/linux/screen_info.h b/include/linux/screen_info.h
>> index eab7081392d50..c764b9a51c24b 100644
>> --- a/include/linux/screen_info.h
>> +++ b/include/linux/screen_info.h
>> @@ -4,6 +4,6 @@
>>
>>   #include <uapi/linux/screen_info.h>
>>
>> -extern struct screen_info screen_info;
>> +#include <asm/screen_info.h>
>>
> 
> What is the purpose of adding a file in asm-generic? If all
> architectures use the same generic file, I'd just leave the
> declaration in include/linux/. I wouldn't bother adding the

That appears a bit 'un-clean' for something that is defined in 
architecture? But OK, I would not object.

> #ifdef either, but I can see how that helps turn a link
> error into an earlier compile error.

Yes, that's intentional. If there's a Kconfig token anyway, we can also 
fail early during the build.

Best regards
Thomas

> 
>        Arnd

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)