ACPI 2.0 / ECDT: Enable correct ECDT initialization order

With wrong ECDT fixes reverted, it is possible to put ECDT probing before
acpi_enable_subsystem().

But the ultimate purpose of ECDT re-enabling is to put the ECDT probing
before the namespace initialization (acpi_load_tables()). This patch
achieves this with protections so that we can enable it later when all
necessary corrections are upstreamed.

Link 4: https://bugzilla.kernel.org/show_bug.cgi?id=112911
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Tested-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index c068c82..31e8da6 100644 (file)
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -925,11 +925,13 @@ void __init acpi_early_init(void)
                goto error0;
        }
 
-       status = acpi_load_tables();
-       if (ACPI_FAILURE(status)) {
-               printk(KERN_ERR PREFIX
-                      "Unable to load the System Description Tables\n");
-               goto error0;
+       if (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;
+               }
        }
 
 #ifdef CONFIG_X86
@@ -995,17 +997,10 @@ static int __init acpi_bus_init(void)
 
        acpi_os_initialize1();
 
-       status = acpi_enable_subsystem(ACPI_NO_ACPI_ENABLE);
-       if (ACPI_FAILURE(status)) {
-               printk(KERN_ERR PREFIX
-                      "Unable to start the ACPI Interpreter\n");
-               goto error1;
-       }
-
        /*
         * 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_initialize_objects()
-        * is called).
+        * 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.
@@ -1013,6 +1008,22 @@ static int __init acpi_bus_init(void)
        status = acpi_ec_ecdt_probe();
        /* Ignore result. Not having an ECDT is not fatal. */
 
+       if (!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_enable_subsystem(ACPI_NO_ACPI_ENABLE);
+       if (ACPI_FAILURE(status)) {
+               printk(KERN_ERR PREFIX
+                      "Unable to start the ACPI Interpreter\n");
+               goto error1;
+       }
+
        status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
        if (ACPI_FAILURE(status)) {
                printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");