On 09/15/2014 10:51 AM, Catalin Marinas wrote:

On Mon, Sep 15, 2014 at 07:28:24AM +0100, Olof Johansson wrote:

quoted

On Fri, Sep 12, 2014 at 10:00:04PM +0800, Hanjun Guo wrote:

quoted

 			See also Documentation/power/runtime_pm.txt, pci=noacpi
 

diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index 9252f72..693da7f 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c

@@ -67,3 +67,18 @@ void __init acpi_boot_table_init(void)
 	if (acpi_table_init())
 		disable_acpi();
 }
+
+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();
+	else
+		return -EINVAL;	/* Core will print when we return error */

For symmetry, you should handle acpi=force here too (i.e. if someone
disables by default, which I expect we'll ask for when this code is
first merged).

Does this mean you want another Kconfig option - ACPI_DEFAULT_OFF (which
would be set by default)?

This would make sense. I mentioned this before since it gives distros an
opportunity to set this differently for their shipping preference
without the upstream having to default to being on.

Jon.