Re: [PATCH v3 6/7] ACPI: enable ACPI_DBG2_TABLE on ARM64

[Aleksey Makarov]

On 03/01/2016 05:52 PM, Peter Hurley wrote:
> On 02/29/2016 04:42 AM, Aleksey Makarov wrote:
>> SBBR mentions DBG2 as a mandatory ACPI table.
>> So enable it for ARM64
> 
> Why does this have to be opted-in per-arch?

DBG2 can specify earlycons.  They should start as soon as possible.
On ARM64 it is just after boot tables become available (in arch_init()).
So it has to be per-arch unless we decide not to start earlycons on 
DBG2 ports.

>> Signed-off-by: Aleksey Makarov <aleksey.makarov@xxxxxxxxxx>
>> ---
>>  arch/arm64/Kconfig       | 1 +
>>  arch/arm64/kernel/acpi.c | 2 ++
>>  2 files changed, 3 insertions(+)
>>
>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>> index 9dc5209..0b614d4 100644
>> --- a/arch/arm64/Kconfig
>> +++ b/arch/arm64/Kconfig
>> @@ -3,6 +3,7 @@ config ARM64
>>  	select ACPI_CCA_REQUIRED if ACPI
>>  	select ACPI_GENERIC_GSI if ACPI
>>  	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
>> +	select ACPI_DBG2_TABLE if ACPI
>>  	select ARCH_HAS_DEVMEM_IS_ALLOWED
>>  	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
>>  	select ARCH_HAS_ELF_RANDOMIZE
>> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
>> index d1ce8e2..3370046 100644
>> --- a/arch/arm64/kernel/acpi.c
>> +++ b/arch/arm64/kernel/acpi.c
>> @@ -208,6 +208,8 @@ void __init acpi_boot_table_init(void)
>>  		pr_err("Failed to init ACPI tables\n");
>>  		if (!param_acpi_force)
>>  			disable_acpi();
>> +	} else {
>> +		acpi_probe_device_table(dbg2);
>>  	}
>>  }
>>  
>>
>