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Date: Wed, 12 Aug 2015 11:12:02 +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 v2] ACPI / EC: Fix an issue caused by the serialized _Qxx evaluations.
It is proven that Windows evaluates _Qxx handlers in a parallel way. This
patch follows this fact, splits _Qxx evaluations from the NOTIFY queue to
form a separate queue, so that _Qxx evaluations can be queued up on
different CPUs rather than being queued up on a CPU0 bound queue.
Event handling related callbacks are also renamed and sorted in this patch.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=94411
Reported-and-tested-by: Gabriele Mazzotta <gabriele.mzt@...il.com>
Signed-off-by: Lv Zheng <lv.zheng@...el.com>
---
drivers/acpi/ec.c | 76 ++++++++++++++++++++++++++++++++++++++---------------
1 file changed, 55 insertions(+), 21 deletions(-)
Index: linux-acpica/drivers/acpi/ec.c
===================================================================
--- linux-acpica.orig/drivers/acpi/ec.c
+++ linux-acpica/drivers/acpi/ec.c
@@ -161,8 +161,16 @@ struct transaction {
u8 flags;
};
+struct acpi_ec_query {
+ struct transaction transaction;
+ struct work_struct work;
+ struct acpi_ec_query_handler *handler;
+};
+
static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
static void advance_transaction(struct acpi_ec *ec);
+static void acpi_ec_event_handler(struct work_struct *work);
+static void acpi_ec_event_processor(struct work_struct *work);
struct acpi_ec *boot_ec, *first_ec;
EXPORT_SYMBOL(first_ec);
@@ -974,60 +982,90 @@ void acpi_ec_remove_query_handler(struct
}
EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
-static void acpi_ec_run(void *cxt)
+static struct acpi_ec_query *acpi_ec_create_query(u8 *pval)
{
- struct acpi_ec_query_handler *handler = cxt;
+ struct acpi_ec_query *q;
+ struct transaction *t;
+
+ q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
+ if (!q)
+ return NULL;
+ INIT_WORK(&q->work, acpi_ec_event_processor);
+ t = &q->transaction;
+ t->command = ACPI_EC_COMMAND_QUERY;
+ t->rdata = pval;
+ t->rlen = 1;
+ return q;
+}
+
+static void acpi_ec_delete_query(struct acpi_ec_query *q)
+{
+ if (q) {
+ if (q->handler)
+ acpi_ec_put_query_handler(q->handler);
+ kfree(q);
+ }
+}
+
+static void acpi_ec_event_processor(struct work_struct *work)
+{
+ struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
+ struct acpi_ec_query_handler *handler = q->handler;
- if (!handler)
- return;
ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
if (handler->func)
handler->func(handler->data);
else if (handler->handle)
acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
- acpi_ec_put_query_handler(handler);
+ acpi_ec_delete_query(q);
}
static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
{
u8 value = 0;
int result;
- acpi_status status;
struct acpi_ec_query_handler *handler;
- struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
- .wdata = NULL, .rdata = &value,
- .wlen = 0, .rlen = 1};
+ struct acpi_ec_query *q;
+
+ q = acpi_ec_create_query(&value);
+ if (!q)
+ return -ENOMEM;
/*
* Query the EC to find out which _Qxx method we need to evaluate.
* Note that successful completion of the query causes the ACPI_EC_SCI
* bit to be cleared (and thus clearing the interrupt source).
*/
- result = acpi_ec_transaction(ec, &t);
- if (result)
- return result;
- if (data)
- *data = value;
+ result = acpi_ec_transaction(ec, &q->transaction);
if (!value)
- return -ENODATA;
+ result = -ENODATA;
+ if (result)
+ goto err_exit;
mutex_lock(&ec->mutex);
list_for_each_entry(handler, &ec->list, node) {
if (value == handler->query_bit) {
- /* have custom handler for this bit */
- handler = acpi_ec_get_query_handler(handler);
+ q->handler = acpi_ec_get_query_handler(handler);
ec_dbg_evt("Query(0x%02x) scheduled",
- handler->query_bit);
- status = acpi_os_execute((handler->func) ?
- OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
- acpi_ec_run, handler);
- if (ACPI_FAILURE(status))
+ 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;
}
}
mutex_unlock(&ec->mutex);
+
+err_exit:
+ if (result && q)
+ acpi_ec_delete_query(q);
+ if (data)
+ *data = value;
return result;
}
--
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