ACPI / EC: Use ec_no_wakeup on Thinkpad X1 Carbon 6th

On this system EC interrupt triggers constantly kicking devices out of
low power states and thus blocking power management. The system also has
a PCIe root port hosting Alpine Ridge Thunderbolt controller and it
never gets a chance to go to D3cold because of this.

Since the power button works the same regardless if EC interrupt is
enabled or not during s2idle, add a quirk for this machine that sets
ec_no_wakeup=true preventing spurious wakeups.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index bb94cf0..442a9e2 100644 (file)
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -2037,6 +2037,17 @@ static inline void acpi_ec_query_exit(void)
        }
 }
 
+static const struct dmi_system_id acpi_ec_no_wakeup[] = {
+       {
+               .ident = "Thinkpad X1 Carbon 6th",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "20KGS3JF01"),
+               },
+       },
+       { },
+};
+
 int __init acpi_ec_init(void)
 {
        int result;
@@ -2047,6 +2058,15 @@ int __init acpi_ec_init(void)
        if (result)
                return result;
 
+       /*
+        * Disable EC wakeup on following systems to prevent periodic
+        * wakeup from EC GPE.
+        */
+       if (dmi_check_system(acpi_ec_no_wakeup)) {
+               ec_no_wakeup = true;
+               pr_debug("Disabling EC wakeup on suspend-to-idle\n");
+       }
+
        /* Drivers must be started after acpi_ec_query_init() */
        dsdt_fail = acpi_bus_register_driver(&acpi_ec_driver);
        /*