ACPICA / Interpreter: Fix a regression triggered because of wrong Linux ECDT support

It is reported that the following commit triggers regressions:
 Linux commit: efaed9be998b5ae0afb7458e057e5f4402b43fa0
 ACPICA commit: 31178590dde82368fdb0f6b0e466b6c0add96c57
 Subject: ACPICA: Events: Enhance acpi_ev_execute_reg_method() to
          ensure no _REG evaluations can happen during OS early boot
          stages

This is because that the ECDT support is not corrected in Linux, and Linux
requires to execute _REG for ECDT (though this sounds so wrong), we need to
ensure acpi_gbl_namespace_initialized is set before ECDT probing in order
for _REG to be executed. Since we have to move
"acpi_gbl_namespace_initialized = TRUE" to the initialization step
happening before ECDT probing, acpi_load_tables() is the best candidate for
now. Thus this patch fixes the regression by doing so.

But if the ECDT support is fixed, Linux will not execute _REG for ECDT, and
ECDT probing will happen before acpi_load_tables(). At that time, we still
want to ensure acpi_gbl_namespace_initialized is set after executing
acpi_ns_initialize_objects() (under the condition of
acpi_gbl_group_module_level_code = FALSE), this patch also moves
acpi_ns_initialize_objects() to acpi_load_tables() accordingly.

Since acpi_ns_initialize_objects() doesn't seem to be skippable, this
patch also removes ACPI_NO_OBJECT_INIT for the one invoked in
acpi_load_tables(). And since the default region handlers should always be
installed before loading the tables, this patch also removes useless
acpi_gbl_group_module_level_code check accordingly. Reported by Chris
Bainbridge, Fixed by Lv Zheng.

Fixes: efaed9be998b (ACPICA: Events: Enhance acpi_ev_execute_reg_method() to ensure no _REG evaluations can happen during OS early boot stages)
Reported-and-tested-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 19 insertions, 7 deletions

diff --git a/drivers/acpi/acpica/tbxfload.c b/drivers/acpi/acpica/tbxfload.c
index 9496b84476a4..3151968c10d1 100644
--- a/drivers/acpi/acpica/tbxfload.c
+++ b/drivers/acpi/acpica/tbxfload.c
@@ -81,13 +81,11 @@ acpi_status __init acpi_load_tables(void)
 	 * between acpi_initialize_subsystem() and acpi_load_tables() to use
 	 * their customized default region handlers.
 	 */
-	if (acpi_gbl_group_module_level_code) {
-		status = acpi_ev_install_region_handlers();
-		if (ACPI_FAILURE(status) && status != AE_ALREADY_EXISTS) {
-			ACPI_EXCEPTION((AE_INFO, status,
-					"During Region initialization"));
-			return_ACPI_STATUS(status);
-		}
+	status = acpi_ev_install_region_handlers();
+	if (ACPI_FAILURE(status) && status != AE_ALREADY_EXISTS) {
+		ACPI_EXCEPTION((AE_INFO, status,
+				"During Region initialization"));
+		return_ACPI_STATUS(status);
 	}
 
 	/* Load the namespace from the tables */
@@ -105,6 +103,20 @@ acpi_status __init acpi_load_tables(void)
 				"While loading namespace from ACPI tables"));
 	}
 
+	if (!acpi_gbl_group_module_level_code) {
+		/*
+		 * Initialize the objects that remain uninitialized. This
+		 * runs the executable AML that may be part of the
+		 * declaration of these objects:
+		 * operation_regions, buffer_fields, Buffers, and Packages.
+		 */
+		status = acpi_ns_initialize_objects();
+		if (ACPI_FAILURE(status)) {
+			return_ACPI_STATUS(status);
+		}
+	}
+
+	acpi_gbl_namespace_initialized = TRUE;
 	return_ACPI_STATUS(status);
 }