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 ++- drivers/acpi/plat/arm-core.c | 21 +++++++++++++++++++++ 2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 8849049..b7e9fc0 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/drivers/acpi/plat/arm-core.c b/drivers/acpi/plat/arm-core.c index c6c7e03..cf46c25 100644 --- a/drivers/acpi/plat/arm-core.c +++ b/drivers/acpi/plat/arm-core.c @@ -108,3 +108,24 @@ 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; + } else { + /* Core will printk when we return error */ + return -EINVAL; + } + + return 0; +} +early_param("acpi", parse_acpi);