Re: [PATCH] arm64: cacheinfo: Simplify init_cache_level()

[Ben Horgan]

Hi Thorsten,

On 04/11/2026 11:07, Thorsten Blum wrote:
> Hi Ben,
> 
> On Wed, Nov 04, 2026 at 10:32:58AM +0000, Ben Horgan wrote:
>> Hi Thorsten,
>>
>> On 04/11/2026 08:36, Thorsten Blum wrote:
>>> acpi_get_cache_info() already sets fw_level to 0 on failure, so drop the
>>> redundant check and the manual assignment.
>>
>> This doesn't seem to be the case when CONFIG_ACPI_PPTT is not defined. Can the dummy implementation
>> in include/linux/cacheinfo.h be called from init_cache_level()? For the implementation in
> 
> On arm64, ACPI_PPTT is selected when ACPI is enabled. When ACPI is
> disabled, acpi_disabled = 1 and init_cache_level() won't call the stub.

Ok, that's true.

> 
>> drivers/acpi/pptt.c levels is documented as "Number of levels if success." and so would be good to
>> mention what happens in the error case if it needs to be relied on.
> 
> Below the parameter descriptions, it already says:
> 
>   "Errors caused by lack of a PPTT table, or otherwise, return 0
>    indicating we didn't find any cache levels."

Ah yes, I should have read on.

Thanks,

Ben

> 
> Thanks,
> Thorsten