Commit 0700c047 authored by Lv Zheng's avatar Lv Zheng Committed by Rafael J. Wysocki
Browse files

ACPI / EC: Fix query handler related issues 



1. acpi_ec_remove_query_handlers()
This patch refines the query handler removal logic implemented in
acpi_ec_remove_query_handler(), making it to invoke new
acpi_ec_remove_query_handlers() API, and ensuring all other removal code
paths to invoke the new API to honor the reference count of the query
handlers.

2. acpi_ec_get_query_handler_by_value()
This patch also refines the query handler search logic originally
implemented in acpi_ec_query(), collecting it into
acpi_ec_get_query_handler_by_value(). And since schedule_work() can ensure
the serilization of acpi_ec_event_handler(), we needn't put the
mutex_lock() around schedule_work().

Signed-off-by: default avatarLv Zheng <lv.zheng@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 15b94fa3

drivers/acpi/ec.c

+45 −28
Original line number Diff line number Diff line
@@ -929,6 +929,23 @@ acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler) 
	return handler;

}



static struct acpi_ec_query_handler *

acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)

{

	struct acpi_ec_query_handler *handler;

	bool found = false;



	mutex_lock(&ec->mutex);

	list_for_each_entry(handler, &ec->list, node) {

		if (value == handler->query_bit) {

			found = true;

			break;

		}

	}

	mutex_unlock(&ec->mutex);

	return found ? acpi_ec_get_query_handler(handler) : NULL;

}



static void acpi_ec_query_handler_release(struct kref *kref)

{

	struct acpi_ec_query_handler *handler =
@@ -964,14 +981,15 @@ int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit, 
}

EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);



void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)

static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,

					  bool remove_all, u8 query_bit)

{

	struct acpi_ec_query_handler *handler, *tmp;

	LIST_HEAD(free_list);



	mutex_lock(&ec->mutex);

	list_for_each_entry_safe(handler, tmp, &ec->list, node) {

		if (query_bit == handler->query_bit) {

		if (remove_all || query_bit == handler->query_bit) {

			list_del_init(&handler->node);

			list_add(&handler->node, &free_list);

		}
@@ -980,6 +998,11 @@ void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit) 
	list_for_each_entry_safe(handler, tmp, &free_list, node)

		acpi_ec_put_query_handler(handler);

}



void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)

{

	acpi_ec_remove_query_handlers(ec, false, query_bit);

}

EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);



static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
@@ -1025,7 +1048,6 @@ static int acpi_ec_query(struct acpi_ec *ec, u8 *data) 
{

	u8 value = 0;

	int result;

	struct acpi_ec_query_handler *handler;

	struct acpi_ec_query *q;



	q = acpi_ec_create_query(&value);
@@ -1043,25 +1065,26 @@ static int acpi_ec_query(struct acpi_ec *ec, u8 *data) 
	if (result)

		goto err_exit;



	mutex_lock(&ec->mutex);

	q->handler = acpi_ec_get_query_handler_by_value(ec, value);

	if (!q->handler) {

		result = -ENODATA;

	list_for_each_entry(handler, &ec->list, node) {

		if (value == handler->query_bit) {

			result = 0;

			q->handler = acpi_ec_get_query_handler(handler);

			ec_dbg_evt("Query(0x%02x) scheduled",

				   q->handler->query_bit);

		goto err_exit;

	}



	/*

			 * It is reported that _Qxx are evaluated in a

			 * parallel way on Windows:

	 * It is reported that _Qxx are evaluated in a parallel way on

	 * Windows:

	 * https://bugzilla.kernel.org/show_bug.cgi?id=94411

	 *

	 * Put this log entry before schedule_work() in order to make

	 * it appearing before any other log entries occurred during the

	 * work queue execution.

	 */

			if (!schedule_work(&q->work))

	ec_dbg_evt("Query(0x%02x) scheduled", value);

	if (!schedule_work(&q->work)) {

		ec_dbg_evt("Query(0x%02x) overlapped", value);

		result = -EBUSY;

			break;

	}

	}

	mutex_unlock(&ec->mutex);



err_exit:

	if (result && q)
@@ -1354,19 +1377,13 @@ static int acpi_ec_add(struct acpi_device *device) 
static int acpi_ec_remove(struct acpi_device *device)

{

	struct acpi_ec *ec;

	struct acpi_ec_query_handler *handler, *tmp;



	if (!device)

		return -EINVAL;



	ec = acpi_driver_data(device);

	ec_remove_handlers(ec);

	mutex_lock(&ec->mutex);

	list_for_each_entry_safe(handler, tmp, &ec->list, node) {

		list_del(&handler->node);

		kfree(handler);

	}

	mutex_unlock(&ec->mutex);

	acpi_ec_remove_query_handlers(ec, true, 0);

	release_region(ec->data_addr, 1);

	release_region(ec->command_addr, 1);

	device->driver_data = NULL;

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