ACPI: TAD: Use DC wakeup only if AC wakeup is supported

According to Section 9.17.2 of ACPI 6.6 [1], setting ACPI_TAD_DC_WAKE in
the capabilities without setting ACPI_TAD_AC_WAKE is invalid, so don't
support wakeup if that's the case.

Moreover, it is sufficient to check ACPI_TAD_AC_WAKE alone to determine
if wakeup is supported at all, so use this observation to simplify one
check.

Link: https://uefi.org/specs/ACPI/6.6/09_ACPI_Defined_Devices_and_Device_Specific_Objects.html#gcp-get-capability
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/2833494.mvXUDI8C0e@rafael.j.wysocki

diff --git a/drivers/acpi/acpi_tad.c b/drivers/acpi/acpi_tad.c
index d67c43edf8558e8d330d6c1ffd89e3028efa015d..8b43d883125ed415edc7459753126aef75c2b1e1 100644 (file)
--- a/drivers/acpi/acpi_tad.c
+++ b/drivers/acpi/acpi_tad.c
@@ -706,6 +706,9 @@ static int acpi_tad_probe(struct platform_device *pdev)
                caps &= ~(ACPI_TAD_AC_WAKE | ACPI_TAD_DC_WAKE);
        }
 
+       if (!(caps & ACPI_TAD_AC_WAKE))
+               caps &= ~ACPI_TAD_DC_WAKE;
+
        dd = devm_kzalloc(dev, sizeof(*dd), GFP_KERNEL);
        if (!dd)
                return -ENOMEM;
@@ -719,7 +722,7 @@ static int acpi_tad_probe(struct platform_device *pdev)
         * runtime suspend.  Everything else should be taken care of by the ACPI
         * PM domain callbacks.
         */
-       if (ACPI_TAD_AC_WAKE | ACPI_TAD_DC_WAKE) {
+       if (ACPI_TAD_AC_WAKE) {
                device_init_wakeup(dev, true);
                dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND |
                                             DPM_FLAG_MAY_SKIP_RESUME);