ACPI / battery: Retry to get battery information if failed during probing

[firefly-linux-kernel-4.4.55.git] / drivers / acpi / battery.c

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 0d7116f34b95aa32f0e2ef044205cdf28df107fe..bc0b286ff2ba92ea8b898388f7fe8e07ad9cc46f 100644 (file)
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -35,6 +35,7 @@
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/suspend.h>
+#include <linux/delay.h>
 #include <asm/unaligned.h>
 
 #ifdef CONFIG_ACPI_PROCFS_POWER
@@ -1151,6 +1152,28 @@ static struct dmi_system_id bat_dmi_table[] = {
        {},
 };
 
+/*
+ * Some machines'(E,G Lenovo Z480) ECs are not stable
+ * during boot up and this causes battery driver fails to be
+ * probed due to failure of getting battery information
+ * from EC sometimes. After several retries, the operation
+ * may work. So add retry code here and 20ms sleep between
+ * every retries.
+ */
+static int acpi_battery_update_retry(struct acpi_battery *battery)
+{
+       int retry, ret;
+
+       for (retry = 5; retry; retry--) {
+               ret = acpi_battery_update(battery, false);
+               if (!ret)
+                       break;
+
+               msleep(20);
+       }
+       return ret;
+}
+
 static int acpi_battery_add(struct acpi_device *device)
 {
        int result = 0;
@@ -1169,9 +1192,11 @@ static int acpi_battery_add(struct acpi_device *device)
        mutex_init(&battery->sysfs_lock);
        if (acpi_has_method(battery->device->handle, "_BIX"))
                set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
-       result = acpi_battery_update(battery, false);
+
+       result = acpi_battery_update_retry(battery);
        if (result)
                goto fail;
+
 #ifdef CONFIG_ACPI_PROCFS_POWER
        result = acpi_battery_add_fs(device);
 #endif