Re: [PATCH v2 05/18] ARM64 / ACPI: Parse FADT table to get PSCI flags for PSCI init

From: Hanjun Guo
Date: Tue Aug 19 2014 - 08:15:28 EST


On 2014-8-19 19:10, Mark Rutland wrote:
>>>> @@ -47,6 +49,26 @@ void __init __acpi_unmap_table(char *map, unsigned long size)
>>>> early_memunmap(map, size);
>>>> }
>>>>
>>>> +static int __init acpi_parse_fadt(struct acpi_table_header *table)
>>>> +{
>>>> + struct acpi_table_fadt *fadt = (struct acpi_table_fadt *)table;
>>>> +
>>>> + /*
>>>> + * Revision in table header is the FADT Major version,
>>>> + * and there is a minor version of FADT which was introduced
>>>> + * by ACPI 5.1, we only deal with ACPI 5.1 or higher version
>>>> + * to get arm boot flags, or we will disable ACPI.
>>>> + */
>>>> + if (table->revision < 5 || fadt->minor_revision < 1) {
>>>
>>> If we ever get revision 6.0, this would trigger.
>>
>> Yes, good catch, actually I already fixed that in my local git repo,
>>
>> + if (table->revision > 5 ||
>> + (table->revision == 5 && fadt->minor_revision >= 1)) {
>> + return 0;
>> + } else {
>> + pr_info("FADT revision is %d.%d, no PSCI support, should be 5.1
>> or higher\n",
>> + table->revision, fadt->minor_revision);
>> + disable_acpi();
>> + return -EINVAL;
>> + }
>
> Given you return in the first path, you don't need the remaining code to
> live in an else block.

Agreed, I will update it, and move disable_acpi() outside this function and keep
it in one place as Sudeep suggested.

Thanks
Hanjun

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