Re: [PATCH v2 2/2] acpi, x86: Use SPCR table for earlycon on x86

From: Ingo Molnar
Date: Tue Dec 12 2017 - 05:41:28 EST



* Prarit Bhargava <prarit@xxxxxxxxxx> wrote:

> The ACPI SPCR code has been used to define an earlycon console for ARM64
> and can be used for x86.
>
> Modify the ACPI SPCR parsing code to account for console behaviour
> differences between ARM64 and x86. Initialize the SPCR code from
> x86 ACPI initialization code.
>
> Signed-off-by: Prarit Bhargava <prarit@xxxxxxxxxx>
> Cc: linux-doc@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-pm@xxxxxxxxxxxxxxx
> Cc: linux-acpi@xxxxxxxxxxxxxxx
> Cc: linux-serial@xxxxxxxxxxxxxxx
> Cc: Bhupesh Sharma <bhsharma@xxxxxxxxxx>
> Cc: Lv Zheng <lv.zheng@xxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> Cc: x86@xxxxxxxxxx
> Cc: Jonathan Corbet <corbet@xxxxxxx>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Will Deacon <will.deacon@xxxxxxx>
> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
> Cc: Timur Tabi <timur@xxxxxxxxxxxxxx>
> ---
> Documentation/admin-guide/kernel-parameters.txt | 3 +++
> arch/arm64/kernel/acpi.c | 2 +-
> arch/x86/kernel/acpi/boot.c | 4 ++++
> drivers/acpi/Kconfig | 2 +-
> drivers/acpi/spcr.c | 7 +++++--
> include/linux/acpi.h | 7 +++++--
> 6 files changed, 19 insertions(+), 6 deletions(-)

LGTM from an x86 perspective:

Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>

(assuming it causes no regressions in linux-next.)

Since patch #1 affects ARM64 significantly, once that patch is acceptable to the
arm64 folks feel free to upstream this second patch via the ARM64 tree as well.

Thanks,

Ingo