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Date: Thu, 24 Sep 2015 14:54:48 +0800
From: Lv Zheng <lv.zheng@...el.com>
To: "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
Len Brown <len.brown@...el.com>
Cc: Lv Zheng <lv.zheng@...el.com>, Lv Zheng <zetalog@...il.com>,
<linux-kernel@...r.kernel.org>, linux-acpi@...r.kernel.org
Subject: [PATCH 2/3] 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: Lv Zheng <lv.zheng@...el.com>
---
drivers/acpi/ec.c | 73 +++++++++++++++++++++++++++++++++--------------------
1 file changed, 45 insertions(+), 28 deletions(-)
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 42c66b6..ddaaa9d 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -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);
- 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);
- /*
- * It is reported that _Qxx are evaluated in a
- * parallel way on Windows:
- * https://bugzilla.kernel.org/show_bug.cgi?id=94411
- */
- if (!schedule_work(&q->work))
- result = -EBUSY;
- break;
- }
+ q->handler = acpi_ec_get_query_handler_by_value(ec, value);
+ if (!q->handler) {
+ result = -ENODATA;
+ goto err_exit;
+ }
+
+ /*
+ * 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.
+ */
+ ec_dbg_evt("Query(0x%02x) scheduled", value);
+ if (!schedule_work(&q->work)) {
+ ec_dbg_evt("Query(0x%02x) overlapped", value);
+ result = -EBUSY;
}
- 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;
--
1.7.10
--
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