On Wed, Jan 14, 2015 at 03:04:52PM +0000, Hanjun Guo wrote:
From: Al Stone al.stone@linaro.org
Introduce one early parameters "off" and "force" for "acpi", acpi=off will be the default behavior for ARM64, so introduce acpi=force to enable ACPI on ARM64.
Disable ACPI before early parameters parsed, and enable it to pass "acpi=force" if people want use ACPI on ARM64. This ensures DT be the prefer one if ACPI table and DT both are provided at this moment.
[...]
--- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -62,6 +62,7 @@ #include <asm/memblock.h> #include <asm/psci.h> #include <asm/efi.h> +#include <asm/acpi.h> unsigned int processor_id; EXPORT_SYMBOL(processor_id); @@ -388,6 +389,8 @@ void __init setup_arch(char **cmdline_p) early_fixmap_init(); early_ioremap_init();
- disable_acpi();
- parse_early_param();
/*
Did we get to any conclusion here? DT being the preferred one is fine when both DT and ACPI are present but do we still want the kernel to ignore ACPI altogether if DT is not present? It's a bit harder to detect the presence of DT at this point since the EFI_STUB added one already. I guess we could move the "acpi=force" argument passing to EFI_STUB if no DT is present at boot.