ACPI / AC: recheck adapter status upon battery status changes

On HP Pavilion dv6-6179er there are no notifications when AC adapter
is plugged/unplugged.
However, when AC status is read (acpi_ac_get_state), and if AC status
has changed, AML code triggers the notification.

This patch solves the problem by re-reading AC adapter status upon
ACPI_BATTERY_NOTIFY_STATUS notification.

Signed-off-by: Alexander Mezin <mezin.alexander@gmail.com>
Acked-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/ac.c b/drivers/acpi/ac.c
index 6f190bc2b8b784bf7e09425b77c560fa60f04b90..2c01c1da29ce39f637136a12a512f2a473333233 100644 (file)
--- a/drivers/acpi/ac.c
+++ b/drivers/acpi/ac.c
@@ -33,6 +33,7 @@
 #include <linux/platform_device.h>
 #include <linux/power_supply.h>
 #include <linux/acpi.h>
+#include "battery.h"
 
 #define PREFIX "ACPI: "
 
@@ -57,6 +58,7 @@ struct acpi_ac {
        struct power_supply charger;
        struct platform_device *pdev;
        unsigned long long state;
+       struct notifier_block battery_nb;
 };
 
 #define to_acpi_ac(x) container_of(x, struct acpi_ac, charger)
@@ -152,6 +154,26 @@ static void acpi_ac_notify_handler(acpi_handle handle, u32 event, void *data)
        return;
 }
 
+static int acpi_ac_battery_notify(struct notifier_block *nb,
+                                 unsigned long action, void *data)
+{
+       struct acpi_ac *ac = container_of(nb, struct acpi_ac, battery_nb);
+       struct acpi_bus_event *event = (struct acpi_bus_event *)data;
+
+       /*
+        * On HP Pavilion dv6-6179er AC status notifications aren't triggered
+        * when adapter is plugged/unplugged. However, battery status
+        * notifcations are triggered when battery starts charging or
+        * discharging. Re-reading AC status triggers lost AC notifications,
+        * if AC status has changed.
+        */
+       if (strcmp(event->device_class, ACPI_BATTERY_CLASS) == 0 &&
+           event->type == ACPI_BATTERY_NOTIFY_STATUS)
+               acpi_ac_get_state(ac);
+
+       return NOTIFY_OK;
+}
+
 static int thinkpad_e530_quirk(const struct dmi_system_id *d)
 {
        ac_sleep_before_get_state_ms = 1000;
@@ -215,6 +237,8 @@ static int acpi_ac_probe(struct platform_device *pdev)
               acpi_device_name(adev), acpi_device_bid(adev),
               ac->state ? "on-line" : "off-line");
 
+       ac->battery_nb.notifier_call = acpi_ac_battery_notify;
+       register_acpi_notifier(&ac->battery_nb);
 end:
        if (result)
                kfree(ac);
@@ -261,6 +285,7 @@ static int acpi_ac_remove(struct platform_device *pdev)
        ac = platform_get_drvdata(pdev);
        if (ac->charger.dev)
                power_supply_unregister(&ac->charger);
+       unregister_acpi_notifier(&ac->battery_nb);
 
        kfree(ac);