Commit cd8c93a4 authored by Alexey Starikovskiy's avatar Alexey Starikovskiy Committed by Len Brown
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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.

Signed-off-by: default avatarAlexey Starikovskiy <>
Signed-off-by: default avatarLen Brown <>
parent f1cd1fe6
......@@ -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;
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) !=
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");
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) {
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