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ACPI: scan: Avoid enumerating devices with clearly invalid _STA values

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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 <salil.mehta@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
This commit is contained in:
Rafael J. Wysocki 2024-04-30 18:02:20 +02:00
parent 829b75d483
commit d4aa921eb8
2 changed files with 12 additions and 1 deletions
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11
drivers/acpi/bus.c
View file

@ -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) {

2
drivers/acpi/scan.c
View file

@ -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,