[PATCH v10 3/4] ARM64: ACPI: enable ACPI_SPCR_TABLE

Hanjun Guo hanjun.guo at linaro.org
Fri Sep 9 02:28:51 PDT 2016


On 2016/9/9 0:34, Mark Salter wrote:
> On Thu, 2016-09-08 at 12:16 +0100, Will Deacon wrote:
>> On Wed, Sep 07, 2016 at 12:30:19PM +0300, Aleksey Makarov wrote:
>>>
>>>
>>> On 09/05/2016 03:36 PM, Aleksey Makarov wrote:
>>>>
>>>> SBBR mentions SPCR as a mandatory ACPI table.  So enable it for ARM64
>>>>
>>>> Earlycon should be set up as early as possible.  ACPI boot tables are
>>>> mapped in arch/arm64/kernel/acpi.c:acpi_boot_table_init() that
>>>> is called from setup_arch() and that's where we parse SPCR.
>>>> So it has to be opted-in per-arch.
>>>>
>>>> When ACPI_SPCR_TABLE is defined initialization of DT earlycon is
>>>> deferred until the DT/ACPI decision is done.  Initialize DT earlycon
>>>> if ACPI is disabled.
>>> Hi Will, Catalin,
>>>
>>> Can you review this patch and consider ACKing it please?
>> Hanjun, Al, Mark, Graeme -- any comments on this?
>>
>> Will
>
> I think there is a problem still with systems using 32-bit access to 8250
> UARTs (i.e. Mustang) but that will need a DBG2 table spec change and
> followup patch to resolve.

Hmm, I think you mean we can add patches later with the spec updated,
and this patch works with SBSA pl011 can go for now?

Thanks
Hanjun



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