Re: [PATCH v1] ACPI: battery: Reduce unnecessary calls to acpi_battery_update()

From: zhangzihuan
Date: Fri May 16 2025 - 01:13:58 EST


Hi Rafael,
Thank you for the review!

在 2025/5/10 02:23, Rafael J. Wysocki 写道:
On Tue, Apr 22, 2025 at 11:11 AM zhangzihuan <zhangzihuan@xxxxxxxxxx> wrote:
When entering the acpi_mattery_notify function, no matter what the event
is, acpi_mattery_update will definitely be called.
I think you mean acpi_battery_update().
Right.
Use the acpi_listen command to listen, sometimes the log looks like this:

battery xxx:00 00000081 00000001
battery xxx:00 00000000 00000001
battery xxx:00 00000080 00000001

Firmware manufacturers will customize some events like 0x0, so
non-matching events will be ignored.
I don't quite get what you are trying to achieve here.

While the laptop is charging, acpi_battery_notify() receives a steady stream of 0x81 events, and only receives 0x80 events
when the battery is almost fully charged or the adapter is plugged in. If acpi_battery_update() is just to
update the battery status,  it didn't need to be called frequently.
Signed-off-by: zhangzihuan <zhangzihuan@xxxxxxxxxx>
---
drivers/acpi/battery.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 6760330a8af5..9446c57b77e7 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -1083,7 +1083,8 @@ static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
msleep(battery_notification_delay_ms);
if (event == ACPI_BATTERY_NOTIFY_INFO)
acpi_battery_refresh(battery);
- acpi_battery_update(battery, false);
+ if (event == ACPI_BATTERY_NOTIFY_STATUS)
+ acpi_battery_update(battery, false);
So only call acpi_battery_update() for ACPI_BATTERY_NOTIFY_STATUS.

Why do you think this is the only case in which acpi_battery_update()
needs to be called?
acpi_battery_update() calls acpi_battery_get_status() to get the battery update status. It will only be updated
if it receives an event that the battery status has changed.
acpi_bus_generate_netlink_event(device->pnp.device_class,
dev_name(&device->dev), event,
acpi_battery_present(battery));
--