@@ -1619,6 +1619,58 @@ error:
return ret;
}
+#ifdef CONFIG_PM_SLEEP
+static void acpi_ec_enter_noirq(struct acpi_ec *ec)
+{
+ unsigned long flags;
+
+ if (ec == first_ec) {
+ spin_lock_irqsave(&ec->lock, flags);
+ ec->saved_busy_polling = ec_busy_polling;
+ ec->saved_polling_guard = ec_polling_guard;
+ ec_busy_polling = true;
+ ec_polling_guard = 0;
+ ec_log_drv("interrupt blocked");
+ spin_unlock_irqrestore(&ec->lock, flags);
+ }
+}
+
+static void acpi_ec_leave_noirq(struct acpi_ec *ec)
+{
+ unsigned long flags;
+
+ if (ec == first_ec) {
+ spin_lock_irqsave(&ec->lock, flags);
+ ec_busy_polling = ec->saved_busy_polling;
+ ec_polling_guard = ec->saved_polling_guard;
+ ec_log_drv("interrupt unblocked");
+ spin_unlock_irqrestore(&ec->lock, flags);
+ }
+}
+
+static int acpi_ec_suspend_noirq(struct device *dev)
+{
+ struct acpi_ec *ec =
+ acpi_driver_data(to_acpi_device(dev));
+
+ acpi_ec_enter_noirq(ec);
+ return 0;
+}
+
+static int acpi_ec_resume_noirq(struct device *dev)
+{
+ struct acpi_ec *ec =
+ acpi_driver_data(to_acpi_device(dev));
+
+ acpi_ec_leave_noirq(ec);
+ return 0;
+}
+#endif
+
+static const struct dev_pm_ops acpi_ec_pm = {
+ SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
+};
+
static int param_set_event_clearing(const char *val, struct kernel_param *kp)
{
int result = 0;
@@ -1664,6 +1716,7 @@ static struct acpi_driver acpi_ec_driver = {
.add = acpi_ec_add,
.remove = acpi_ec_remove,
},
+ .drv.pm = &acpi_ec_pm,
};
static inline int acpi_ec_query_init(void)
@@ -174,6 +174,8 @@ struct acpi_ec {
struct work_struct work;
unsigned long timestamp;
unsigned long nr_pending_queries;
+ bool saved_busy_polling;
+ unsigned int saved_polling_guard;
};
extern struct acpi_ec *first_ec;
It is reported that on some platforms, resume speed is not fast. The cause is: in noirq stage, EC driver is working in polling mode, and each state machine advancement requires a context switch. The context switch is not necessary to the EC driver's polling mode. This patch implements PM hooks to automatically switch the driver to/from the busy polling mode to eliminate the overhead caused by the context switch. This finally contributes to the tuning result: acpi_pm_finish() execution time is improved from 192ms to 6ms. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Reported-and-tested-by: Todd E Brandt <todd.e.brandt@linux.intel.com> --- drivers/acpi/ec.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++ drivers/acpi/internal.h | 2 ++ 2 files changed, 55 insertions(+)