ACPI: battery: check for battery present on /proc/battery access

http://bugzilla.kernel.org/show_bug.cgi?id=7200

Signed-off-by: Vladimir Lebedev <vladimir.p.lebedev@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 2f4521a48fe7..0d7a32e502d1 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -324,6 +324,13 @@ static int acpi_battery_check(struct acpi_battery *battery)
         return result;
 }
 
+static void acpi_battery_check_present(struct acpi_battery *battery)
+{
+        if (!battery->flags.present) {
+                acpi_battery_check(battery);
+        }
+}
+
 /* --------------------------------------------------------------------------
                               FS Interface (/proc)
    -------------------------------------------------------------------------- */
@@ -340,6 +347,8 @@ static int acpi_battery_read_info(struct seq_file *seq, void *offset)
         if (!battery)
                 goto end;
 
+        acpi_battery_check_present(battery);
+
         if (battery->flags.present)
                 seq_printf(seq, "present:                 yes\n");
         else {
@@ -424,6 +433,8 @@ static int acpi_battery_read_state(struct seq_file *seq, void *offset)
         if (!battery)
                 goto end;
 
+        acpi_battery_check_present(battery);
+
         if (battery->flags.present)
                 seq_printf(seq, "present:                 yes\n");
         else {
@@ -499,6 +510,8 @@ static int acpi_battery_read_alarm(struct seq_file *seq, void *offset)
         if (!battery)
                 goto end;
 
+        acpi_battery_check_present(battery);
+
         if (!battery->flags.present) {
                 seq_printf(seq, "present:                 no\n");
                 goto end;
@@ -536,6 +549,8 @@ acpi_battery_write_alarm(struct file *file,
         if (!battery || (count > sizeof(alarm_string) - 1))
                 return -EINVAL;
 
+        acpi_battery_check_present(battery);
+
         if (!battery->flags.present)
                 return -ENODEV;