From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> The return value of _STA with the "present" bit unset and the "enabled" bit set is clearly invalid as per the ACPI specification, Section 6.3.7 "_STA (Device Status)", so make the ACPI device enumeration code disregard devices with such _STA return values. Also, because this implies that status.enabled will only be set if status.present is set too, acpi_device_is_enabled() can be modified to simply return the value of the former. Link: https://uefi.org/specs/ACPI/6.5/06_Device_Configuration.html#sta-device-status Link: https://lore.kernel.org/linux-acpi/88179311a503493099028c12ca37d430@xxxxxxxxxx/ Suggested-by: Salil Mehta <salil.mehta@xxxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> --- v1 -> v2: * Fix a confusing comment. * Add R-by from Jonathan (thank you!) --- drivers/acpi/bus.c | 11 +++++++++++ drivers/acpi/scan.c | 2 +- 2 files changed, 12 insertions(+), 1 deletion(-) Index: linux-pm/drivers/acpi/bus.c =================================================================== --- linux-pm.orig/drivers/acpi/bus.c +++ linux-pm/drivers/acpi/bus.c @@ -112,6 +112,17 @@ int acpi_bus_get_status(struct acpi_devi if (ACPI_FAILURE(status)) return -ENODEV; + if (!device->status.present && device->status.enabled) { + pr_info(FW_BUG "Device [%s] status [%08x]: not present and enabled\n", + device->pnp.bus_id, (u32)sta); + device->status.enabled = 0; + /* + * The status is clearly invalid, so clear the functional bit as + * well to avoid attempting to use the device. + */ + device->status.functional = 0; + } + acpi_set_device_status(device, sta); if (device->status.functional && !device->status.present) { Index: linux-pm/drivers/acpi/scan.c =================================================================== --- linux-pm.orig/drivers/acpi/scan.c +++ linux-pm/drivers/acpi/scan.c @@ -1962,7 +1962,7 @@ bool acpi_device_is_present(const struct bool acpi_device_is_enabled(const struct acpi_device *adev) { - return adev->status.present && adev->status.enabled; + return adev->status.enabled; } static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
