[PATCH 4.19 55/58] ACPI: probe ECDT before loading AML tables regardless of module-level code flag

Greg Kroah-Hartman
2021-06-08T18:43:58Z

From: Erik Schmauss <erik.schmauss@intel.com>

commit d737f333b211361b6e239fc753b84c3be2634aaa upstream.

It was discovered that AML tables were loaded before or after the
ECDT depending on acpi_gbl_execute_tables_as_methods. According to
the ACPI spec, the ECDT should be loaded before the namespace is
populated by loading AML tables (DSDT and SSDT). Since the ECDT
should be loaded early in the boot process, this change moves the
ECDT probing to acpi_early_init.

Signed-off-by: Erik Schmauss <erik.schmauss@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Laurențiu Păncescu <lpancescu@gmail.com>
Cc: Salvatore Bonaccorso <carnil@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/acpi/bus.c | 44 ++++++++++++++++----------------------------
1 file changed, 16 insertions(+), 28 deletions(-)

--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -1054,15 +1054,17 @@ void __init acpi_early_init(void)
goto error0;
}

- if (!acpi_gbl_execute_tables_as_methods &&
- acpi_gbl_group_module_level_code) {
- status = acpi_load_tables();
- if (ACPI_FAILURE(status)) {
- printk(KERN_ERR PREFIX
- "Unable to load the System Description Tables\n");
- goto error0;
- }
- }
+ /*
+ * ACPI 2.0 requires the EC driver to be loaded and work before
+ * the EC device is found in the namespace (i.e. before
+ * acpi_load_tables() is called).
+ *
+ * This is accomplished by looking for the ECDT table, and getting
+ * the EC parameters out of that.
+ *
+ * Ignore the result. Not having an ECDT is not fatal.
+ */
+ status = acpi_ec_ecdt_probe();

#ifdef CONFIG_X86
if (!acpi_ioapic) {
@@ -1133,25 +1135,11 @@ static int __init acpi_bus_init(void)

acpi_os_initialize1();

- /*
- * ACPI 2.0 requires the EC driver to be loaded and work before
- * the EC device is found in the namespace (i.e. before
- * acpi_load_tables() is called).
- *
- * This is accomplished by looking for the ECDT table, and getting
- * the EC parameters out of that.
- */
- status = acpi_ec_ecdt_probe();
- /* Ignore result. Not having an ECDT is not fatal. */
-
- if (acpi_gbl_execute_tables_as_methods ||
- !acpi_gbl_group_module_level_code) {
- status = acpi_load_tables();
- if (ACPI_FAILURE(status)) {
- printk(KERN_ERR PREFIX
- "Unable to load the System Description Tables\n");
- goto error1;
- }
+ status = acpi_load_tables();
+ if (ACPI_FAILURE(status)) {
+ printk(KERN_ERR PREFIX
+ "Unable to load the System Description Tables\n");
+ goto error1;
}

status = acpi_enable_subsystem(ACPI_NO_ACPI_ENABLE);