ACPI: EC: If ECDT is not found, look up EC in DSDT.

Some ASUS laptops access EC space from device _INI methods, but do not
provide ECDT for early EC setup. In order to make them function properly,
there is a need to find EC is DSDT before any _INI is called.

Similar functionality was turned on by acpi_fake_ecdt=1 command line
before. Now it is on all the time.

http://bugzilla.kernel.org/show_bug.cgi?id=8598

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index dd384ec..4d7fe82 100644 (file)
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -664,30 +664,32 @@ acpi_ec_register_query_methods(acpi_handle handle, u32 level,
        return AE_OK;
 }
 
-static int ec_parse_device(struct acpi_ec *ec, acpi_handle handle)
+static acpi_status
+ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 {
-       if (ACPI_FAILURE(acpi_walk_resources(handle, METHOD_NAME__CRS,
-                                    ec_parse_io_ports, ec)))
-               return -EINVAL;
+       acpi_status status;
+
+       struct acpi_ec *ec = context;
+       status = acpi_walk_resources(handle, METHOD_NAME__CRS,
+                                    ec_parse_io_ports, ec);
+       if (ACPI_FAILURE(status))
+               return status;
 
        /* Get GPE bit assignment (EC events). */
        /* TODO: Add support for _GPE returning a package */
-       if (ACPI_FAILURE(acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe)))
-               return -EINVAL;
+       status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe);
+       if (ACPI_FAILURE(status))
+               return status;
 
        /* Use the global lock for all EC transactions? */
        acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
 
-       /* Find and register all query methods */
-       acpi_walk_namespace(ACPI_TYPE_METHOD, handle, 1,
-                           acpi_ec_register_query_methods, ec, NULL);
-
        ec->handle = handle;
 
        printk(KERN_INFO PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx",
                          ec->gpe, ec->command_addr, ec->data_addr);
 
-       return 0;
+       return AE_CTRL_TERMINATE;
 }
 
 static int acpi_ec_add(struct acpi_device *device)
@@ -704,7 +706,8 @@ static int acpi_ec_add(struct acpi_device *device)
        if (!ec)
                return -ENOMEM;
 
-       if (ec_parse_device(ec, device->handle)) {
+       if (ec_parse_device(device->handle, 0, ec, NULL) !=
+           AE_CTRL_TERMINATE) {
                kfree(ec);
                return -EINVAL;
        }
@@ -867,18 +870,21 @@ int __init acpi_ec_ecdt_probe(void)
        /*
         * Generate a boot ec context
         */
-
        status = acpi_get_table(ACPI_SIG_ECDT, 1,
                                (struct acpi_table_header **)&ecdt_ptr);
-       if (ACPI_FAILURE(status))
-               goto error;
-
-       printk(KERN_INFO PREFIX "EC description table is found, configuring boot EC\n");
-
-       boot_ec->command_addr = ecdt_ptr->control.address;
-       boot_ec->data_addr = ecdt_ptr->data.address;
-       boot_ec->gpe = ecdt_ptr->gpe;
-       boot_ec->handle = ACPI_ROOT_OBJECT;
+       if (ACPI_SUCCESS(status)) {
+               printk(KERN_INFO PREFIX "EC description table is found, configuring boot EC\n\n");
+               boot_ec->command_addr = ecdt_ptr->control.address;
+               boot_ec->data_addr = ecdt_ptr->data.address;
+               boot_ec->gpe = ecdt_ptr->gpe;
+               boot_ec->handle = ACPI_ROOT_OBJECT;
+       } else {
+               printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
+               status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
+                                               boot_ec, NULL);
+               if (ACPI_FAILURE(status))
+                       goto error;
+       }
 
        ret = ec_install_handlers(boot_ec);
        if (!ret) {