ACPI: EC: Accelerate query execution
Split EC query handling into acknowledge and execution phase.
This allows much smaller pending query lattency and lowers chances
of EC going "wild" and losing events.
Reference: http://bugzilla.kernel.org/show_bug.cgi?id=14858
Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index fd1801b..9cc3885 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -201,14 +201,13 @@
spin_unlock_irqrestore(&ec->curr_lock, flags);
}
-static void acpi_ec_gpe_query(void *ec_cxt);
+static int acpi_ec_sync_query(struct acpi_ec *ec);
-static int ec_check_sci(struct acpi_ec *ec, u8 state)
+static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
{
if (state & ACPI_EC_FLAG_SCI) {
if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
- return acpi_os_execute(OSL_EC_BURST_HANDLER,
- acpi_ec_gpe_query, ec);
+ return acpi_ec_sync_query(ec);
}
return 0;
}
@@ -249,11 +248,6 @@
{
unsigned long tmp;
int ret = 0;
- pr_debug(PREFIX "transaction start\n");
- /* disable GPE during transaction if storm is detected */
- if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
- acpi_disable_gpe(NULL, ec->gpe);
- }
if (EC_FLAGS_MSI)
udelay(ACPI_EC_MSI_UDELAY);
/* start transaction */
@@ -269,16 +263,6 @@
spin_lock_irqsave(&ec->curr_lock, tmp);
ec->curr = NULL;
spin_unlock_irqrestore(&ec->curr_lock, tmp);
- if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
- /* check if we received SCI during transaction */
- ec_check_sci(ec, acpi_ec_read_status(ec));
- /* it is safe to enable GPE outside of transaction */
- acpi_enable_gpe(NULL, ec->gpe);
- } else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
- pr_info(PREFIX "GPE storm detected, "
- "transactions will use polling mode\n");
- set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
- }
return ret;
}
@@ -321,7 +305,24 @@
status = -ETIME;
goto end;
}
+ pr_debug(PREFIX "transaction start\n");
+ /* disable GPE during transaction if storm is detected */
+ if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
+ acpi_disable_gpe(NULL, ec->gpe);
+ }
+
status = acpi_ec_transaction_unlocked(ec, t);
+
+ /* check if we received SCI during transaction */
+ ec_check_sci_sync(ec, acpi_ec_read_status(ec));
+ if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
+ /* it is safe to enable GPE outside of transaction */
+ acpi_enable_gpe(NULL, ec->gpe);
+ } else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) {
+ pr_info(PREFIX "GPE storm detected, "
+ "transactions will use polling mode\n");
+ set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
+ }
end:
if (ec->global_lock)
acpi_release_global_lock(glk);
@@ -443,7 +444,7 @@
EXPORT_SYMBOL(ec_transaction);
-static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
+static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
{
int result;
u8 d;
@@ -452,20 +453,16 @@
.wlen = 0, .rlen = 1};
if (!ec || !data)
return -EINVAL;
-
/*
* 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);
+ result = acpi_ec_transaction_unlocked(ec, &t);
if (result)
return result;
-
if (!d)
return -ENODATA;
-
*data = d;
return 0;
}
@@ -509,43 +506,78 @@
EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
-static void acpi_ec_gpe_query(void *ec_cxt)
+static void acpi_ec_run(void *cxt)
{
- struct acpi_ec *ec = ec_cxt;
- u8 value = 0;
- struct acpi_ec_query_handler *handler, copy;
-
- if (!ec || acpi_ec_query(ec, &value))
+ struct acpi_ec_query_handler *handler = cxt;
+ if (!handler)
return;
- mutex_lock(&ec->lock);
+ pr_debug(PREFIX "start query execution\n");
+ if (handler->func)
+ handler->func(handler->data);
+ else if (handler->handle)
+ acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
+ pr_debug(PREFIX "stop query execution\n");
+ kfree(handler);
+}
+
+static int acpi_ec_sync_query(struct acpi_ec *ec)
+{
+ u8 value = 0;
+ int status;
+ struct acpi_ec_query_handler *handler, *copy;
+ if ((status = acpi_ec_query_unlocked(ec, &value)))
+ return status;
list_for_each_entry(handler, &ec->list, node) {
if (value == handler->query_bit) {
/* have custom handler for this bit */
- memcpy(©, handler, sizeof(copy));
- mutex_unlock(&ec->lock);
- if (copy.func) {
- copy.func(copy.data);
- } else if (copy.handle) {
- acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
- }
- return;
+ copy = kmalloc(sizeof(*handler), GFP_KERNEL);
+ if (!copy)
+ return -ENOMEM;
+ memcpy(copy, handler, sizeof(*copy));
+ pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
+ return acpi_os_execute(OSL_GPE_HANDLER,
+ acpi_ec_run, copy);
}
}
+ return 0;
+}
+
+static void acpi_ec_gpe_query(void *ec_cxt)
+{
+ struct acpi_ec *ec = ec_cxt;
+ if (!ec)
+ return;
+ mutex_lock(&ec->lock);
+ acpi_ec_sync_query(ec);
mutex_unlock(&ec->lock);
}
+static void acpi_ec_gpe_query(void *ec_cxt);
+
+static int ec_check_sci(struct acpi_ec *ec, u8 state)
+{
+ if (state & ACPI_EC_FLAG_SCI) {
+ if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
+ pr_debug(PREFIX "push gpe query to the queue\n");
+ return acpi_os_execute(OSL_NOTIFY_HANDLER,
+ acpi_ec_gpe_query, ec);
+ }
+ }
+ return 0;
+}
+
static u32 acpi_ec_gpe_handler(void *data)
{
struct acpi_ec *ec = data;
- u8 status;
pr_debug(PREFIX "~~~> interrupt\n");
- status = acpi_ec_read_status(ec);
- advance_transaction(ec, status);
- if (ec_transaction_done(ec) && (status & ACPI_EC_FLAG_IBF) == 0)
+ advance_transaction(ec, acpi_ec_read_status(ec));
+ if (ec_transaction_done(ec) &&
+ (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
wake_up(&ec->wait);
- ec_check_sci(ec, status);
+ ec_check_sci(ec, acpi_ec_read_status(ec));
+ }
return ACPI_INTERRUPT_HANDLED;
}