From 48eab1c5e0d9fe67384d6c2e91efdf0ec3ff54b5 Mon Sep 17 00:00:00 2001 From: Maximilian Luz Date: Tue, 8 Feb 2022 01:29:48 +0100 Subject: [PATCH] ACPI: battery: Add "Not Charging" quirk for Microsoft Surface devices Microsoft Surface devices have a limiter that sets a fixed maximum charge capacity for the battery. When that maximum capacity has been reached, charging stops. In that case, _BST returns a battery state field with both "charging" and "discharging" bits cleared. The battery driver, however, returns "unknown" as status. This seems to be the same behavior as observed on the ThinkPads, so let's use the same quirk to handle that as well. Signed-off-by: Maximilian Luz Patchset: surface-battery --- For what it's worth, I don't think the ACPI spec explicitly states that any of the status bits need to be set, or that there are only the "charging" and "discharging" states. As far as I can tell, ACPI only states: Notice that the Charging bit and the Discharging bit are mutually exclusive and must not both be set at the same time. Even in critical state, hardware should report the corresponding charging/discharging state. But that does not exclude the case that no bit is set. So, strictly going by spec, I don't think it's necessary to put all of this behind a quirk. --- drivers/acpi/battery.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c index dc208f5f5a1f..db2aa56c746a 100644 --- a/drivers/acpi/battery.c +++ b/drivers/acpi/battery.c @@ -1152,6 +1152,14 @@ static const struct dmi_system_id bat_dmi_table[] __initconst = { DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad"), }, }, + { + .callback = battery_quirk_not_charging, + .ident = "Microsoft Surface", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"), + DMI_MATCH(DMI_PRODUCT_NAME, "Surface"), + }, + }, { /* Microsoft Surface Go 3 */ .callback = battery_notification_delay_quirk, -- 2.36.0