Commit 97cb159f authored by Lv Zheng's avatar Lv Zheng Committed by Rafael J. Wysocki
Browse files

ACPI / EC: Fix issues related to boot_ec 

There are issues related to the boot_ec:
1. If acpi_ec_remove() is invoked, boot_ec will also be freed, this is not
   expected as the boot_ec could be enumerated via ECDT.
2. Address space handler installation/unstallation lead to unexpected _REG
   evaluations.
This patch adds acpi_is_boot_ec() check to be used to fix the above issues.
However, since acpi_ec_remove() actually won't be invoked, this patch
doesn't handle the reference counting of "struct acpi_ec", it only ensures
the correctness of the boot_ec destruction during the boot.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=153511


Reported-and-tested-by: default avatarJonh Henderson <jw.hendy@gmail.com>
Signed-off-by: default avatarLv Zheng <lv.zheng@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 2a570840

drivers/acpi/ec.c

+49 −14
Original line number Diff line number Diff line
@@ -1536,6 +1536,37 @@ static int acpi_config_boot_ec(struct acpi_ec *ec, acpi_handle handle, 
	return ret;

}



static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle)

{

	struct acpi_table_ecdt *ecdt_ptr;

	acpi_status status;

	acpi_handle handle;



	status = acpi_get_table(ACPI_SIG_ECDT, 1,

				(struct acpi_table_header **)&ecdt_ptr);

	if (ACPI_FAILURE(status))

		return false;



	status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);

	if (ACPI_FAILURE(status))

		return false;



	*phandle = handle;

	return true;

}



static bool acpi_is_boot_ec(struct acpi_ec *ec)

{

	if (!boot_ec)

		return false;

	if (ec->handle == boot_ec->handle &&

	    ec->gpe == boot_ec->gpe &&

	    ec->command_addr == boot_ec->command_addr &&

	    ec->data_addr == boot_ec->data_addr)

		return true;

	return false;

}



static int acpi_ec_add(struct acpi_device *device)

{

	struct acpi_ec *ec = NULL;
@@ -1553,7 +1584,14 @@ static int acpi_ec_add(struct acpi_device *device) 
			goto err_alloc;

	}



	ret = acpi_config_boot_ec(ec, device->handle, true, false);

	if (acpi_is_boot_ec(ec)) {

		boot_ec_is_ecdt = false;

		acpi_handle_debug(ec->handle, "duplicated.\n");

		acpi_ec_free(ec);

		ec = boot_ec;

		ret = acpi_config_boot_ec(ec, ec->handle, true, false);

	} else

		ret = acpi_ec_setup(ec, true);

	if (ret)

		goto err_query;
@@ -1566,11 +1604,14 @@ static int acpi_ec_add(struct acpi_device *device) 


	/* Reprobe devices depending on the EC */

	acpi_walk_dep_device_list(ec->handle);

	acpi_handle_debug(ec->handle, "enumerated.\n");

	return 0;



err_query:

	if (ec != boot_ec)

		acpi_ec_remove_query_handlers(ec, true, 0);

err_alloc:

	if (ec != boot_ec)

		acpi_ec_free(ec);

	return ret;

}
@@ -1583,11 +1624,13 @@ static int acpi_ec_remove(struct acpi_device *device) 
		return -EINVAL;



	ec = acpi_driver_data(device);

	ec_remove_handlers(ec);

	release_region(ec->data_addr, 1);

	release_region(ec->command_addr, 1);

	device->driver_data = NULL;

	if (ec != boot_ec) {

		ec_remove_handlers(ec);

		acpi_ec_free(ec);

	}

	return 0;

}
@@ -1659,8 +1702,6 @@ error: 
 */

int __init acpi_ec_ecdt_start(void)

{

	struct acpi_table_ecdt *ecdt_ptr;

	acpi_status status;

	acpi_handle handle;



	if (!boot_ec)
@@ -1672,17 +1713,11 @@ int __init acpi_ec_ecdt_start(void) 
	if (!boot_ec_is_ecdt)

		return -ENODEV;



	status = acpi_get_table(ACPI_SIG_ECDT, 1,

				(struct acpi_table_header **)&ecdt_ptr);

	if (ACPI_FAILURE(status))

		return -ENODEV;



	/*

	 * At this point, the namespace and the GPE is initialized, so

	 * start to find the namespace objects and handle the events.

	 */

	status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);

	if (ACPI_FAILURE(status))

	if (!acpi_ec_ecdt_get_handle(&handle))

		return -ENODEV;

	return acpi_config_boot_ec(boot_ec, handle, true, true);

}

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