From: Jiri Kosina <jikos@xxxxxxxx>
There is a problem in th following scenario(s):
boot -> suspend -> (un)plug battery -> resume
The problem arises in both cases - i.e. suspend with battery plugged in,
and resume with battery unplugged, or vice versa.
After resume, when the battery status has changed (plugged in -> unplegged
or unplugged -> plugged in) during the time when the system was sleeping,
the /proc/acpi/battery/*/* is wrong (showing the state before suspend, not
the current state).
The following patch adds ->resume method to the ACPI battery handler, which
has the only aim - to check whether the battery state has changed during
sleep, and if so, update the ACPI internal data structures, so that
information published through /proc/acpi/battery/*/* is correct even after
suspend/resume cycle, during which the battery was removed/inserted.
The patch is against current ACPI git tree, but applies cleanly also
against -mm and probably other trees. Please apply.
Signed-off-by: Jiri Kosina <jikos@xxxxxxxx>
Cc: "Brown, Len" <len.brown@xxxxxxxxx>
Cc: Stefan Seyfried <seife@xxxxxxx>
Acked-by: Pavel Machek <pavel@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/acpi/battery.c | 14 ++++++++++++++
1 files changed, 14 insertions(+)
diff -puN drivers/acpi/battery.c~acpi-preserve-correct-battery-state-through-suspend-resume-cycles drivers/acpi/battery.c
--- a/drivers/acpi/battery.c~acpi-preserve-correct-battery-state-through-suspend-resume-cycles
+++ a/drivers/acpi/battery.c
@@ -64,6 +64,7 @@ extern void *acpi_unlock_battery_dir(str
static int acpi_battery_add(struct acpi_device *device);
static int acpi_battery_remove(struct acpi_device *device, int type);
+static int acpi_battery_resume(struct acpi_device *device, int status);
static struct acpi_driver acpi_battery_driver = {
.name = ACPI_BATTERY_DRIVER_NAME,
@@ -71,6 +72,7 @@ static struct acpi_driver acpi_battery_d
.ids = ACPI_BATTERY_HID,
.ops = {
.add = acpi_battery_add,
+ .resume = acpi_battery_resume,
.remove = acpi_battery_remove,
},
};
@@ -753,6 +755,18 @@ static int acpi_battery_remove(struct ac
return 0;
}
+/* this is needed to learn about changes made in suspended state */
+static int acpi_battery_resume(struct acpi_device *device, int state)
+{
+ struct acpi_battery *battery;
+
+ if (!device)
+ return -EINVAL;
+
+ battery = device->driver_data;
+ return acpi_battery_check(battery);
+}
+
static int __init acpi_battery_init(void)
{
int result;
_
-
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