On the Lenovo Yoga S740-14IIL (81RS, BIOS BYCN29WW), the ECDT advertises GPE 0x6E for the embedded controller, but the EC is actually wired to GPE 0x43, which is what the DSDT EC0 device's _GPE method returns. Since the ECDT and DSDT EC share the same command/data ports (0x66/0x62), acpi_ec_add() keeps the ECDT GPE, so no EC events are ever handled: ACPI: EC: GPE=0x6e /sys/firmware/acpi/interrupts/gpe6E: 0 EN enabled unmasked /sys/firmware/acpi/interrupts/gpe43: 0 EN STS invalid unmasked GPE 0x6E never fires, while GPE 0x43 is left enabled with its status bit set and no handler, so each SCI it raises is counted in sci_not (about 7/s, 1.4 million over 55 hours of uptime). As a result, EC query events are lost: the brightness hotkeys and several other Fn hotkeys produce no input events at all, and battery/AC notifications/ laptop lid event are not delivered. Add the machine to ec_dmi_table so that the DSDT GPE is used. Tested by overriding the ECDT through the initrd with a copy whose GPE was changed from 0x6E to 0x43, and later by applying this patch and removing the override. With the fix the kernel reports "ACPI: EC: GPE=0x43", gpe43 receives events, sci_not stays at 0, and the brightness and other Fn hotkeys work. Cc: stable@vger.kernel.org Signed-off-by: Amir Sabbaghi --- drivers/acpi/ec.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index a89f10256..7c0643d5d 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -2007,6 +2007,16 @@ static const struct dmi_system_id ec_dmi_table[] __initconst = { DMI_MATCH(DMI_PRODUCT_NAME, "HP 250 G7 Notebook PC"), }, }, + { + /* + * Lenovo Yoga S740-14IIL + */ + .callback = ec_honor_dsdt_gpe, + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), + DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo Yoga S740-14IIL"), + }, + }, { /* * Samsung hardware -- 2.54.0