[PATCH 3/3] cmd: acpi: check HW reduced flag in acpi list

[Heinrich Schuchardt]

On 12/15/23 18:46, Andy Shevchenko wrote:
> On Fri, Dec 15, 2023 at 05:40:16PM +0100, Heinrich Schuchardt wrote:
>> On non x86 platforms the hardware reduce flag must be set in the FADT
>> table. Write an error message if the flag is missing.
> 
> ...
> 
>> +	if (!IS_ENABLED(CONFIG_X86) &&
>> +	    !(fadt->flags & ACPI_FADT_HW_REDUCED_ACPI))
>> +		log_err("FADT not ACPI hardware reduced compliant\n");
> 
> I guess it's half baked solution as this, HW reduced, flag adds more
> limitations even on x86. If you want a good validation it should be done
> in a separate function taking others aspects into account.
> 
> But since it doesn't affect my area of interest in U-Boot, I won't prevent
> you from doing this way, it's up to the U-Boot maintainers how to proceed
> with it.
> 

This flag is checked by Linux. It won't boot at all if the flag is not 
set on arm64 or riscv64. See arch/arm64/kernel/acpi.c and 
arch/riscv/kernel/acpi.c, function acpi_fadt_sanity_check().

Once you have booted you can use the Firmware Test Suite (FWTS) to check 
the rest. I don't plan rewriting such a validation in U-Boot.

Best regards

Heinrich