From d4aa921eb85a74bf0502eff64f0b9e06fe17081b Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 30 Apr 2024 18:02:20 +0200 Subject: ACPI: scan: Avoid enumerating devices with clearly invalid _STA values 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@huawei.com/ Suggested-by: Salil Mehta Signed-off-by: Rafael J. Wysocki Reviewed-by: Jonathan Cameron Reviewed-by: Sudeep Holla --- drivers/acpi/bus.c | 11 +++++++++++ drivers/acpi/scan.c | 2 +- 2 files changed, 12 insertions(+), 1 deletion(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index d9fa730416f1..18d50448ae1c 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -112,6 +112,17 @@ int acpi_bus_get_status(struct acpi_device *device) 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) { diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 68f101323f53..e41fb5716bc0 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1962,7 +1962,7 @@ bool acpi_device_is_present(const struct acpi_device *adev) 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, -- cgit v1.2.3