[PATCH 02/19] ARM64 / ACPI: Introduce early_param for "acpi"

Sudeep Holla
2014-07-28T18:35:45Z

On 24/07/14 14:00, Hanjun Guo wrote:
> From: Al Stone <al.stone@linaro.org>
>
> Introduce two early parameters for "acpi", one is the parameter
> to disable ACPI on ARM64 and another one is acpi=strict to disable
> out-of-spec workarounds.
>
> Reviewed-by: Grant Likely <grant.likely@linaro.org>
> Signed-off-by: Al Stone <al.stone@linaro.org>
> Signed-off-by: Graeme Gregory <graeme.gregory@linaro.org>
> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
> ---
> Documentation/kernel-parameters.txt | 3 ++-
> arch/arm64/kernel/acpi.c | 21 +++++++++++++++++++++
> 2 files changed, 23 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index b7fa2f5..d130bd5 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -165,7 +165,7 @@ multipliers 'Kilo', 'Mega', and 'Giga', equalling 2^10, 2^20, and 2^30
> bytes respectively. Such letter suffixes can also be entirely omitted.
>
>
> - acpi= [HW,ACPI,X86]
> + acpi= [HW,ACPI,X86,ARM]
> Advanced Configuration and Power Interface
> Format: { force | off | strict | noirq | rsdt }
> force -- enable ACPI if default was off
> @@ -175,6 +175,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
> strictly ACPI specification compliant.
> rsdt -- prefer RSDT over (default) XSDT
> copy_dsdt -- copy DSDT to memory
> + For ARM64, ONLY "off" and "strict" are available.
>
> See also Documentation/power/runtime_pm.txt, pci=noacpi
>
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> index c62fce6..ac78e4e 100644
> --- a/arch/arm64/kernel/acpi.c
> +++ b/arch/arm64/kernel/acpi.c
> @@ -74,3 +74,24 @@ void __init acpi_boot_table_init(void)
> return;
> }
> }
> +
> +static int __init parse_acpi(char *arg)
> +{
> + if (!arg)
> + return -EINVAL;
> +
> + /* "acpi=off" disables both ACPI table parsing and interpreter */
> + if (strcmp(arg, "off") == 0) {
> + disable_acpi();
> + }
> + /* acpi=strict disables out-of-spec workarounds */
> + else if (strcmp(arg, "strict") == 0) {
> + acpi_strict = 1;

This should be default set as I mentioned in patch#1. We can introduce
this option if required in future.

Regards,
Sudeep