Evaluating acpi _BCL could be failed, then acpi buffer size will be set to 0. When reuse this acpi buffer, AE_BUFFER_OVERFLOW will be triggered. Re-initialize buffer size will make acpi evaluate successfully. Signed-off-by: Aaron Ma <aaron.ma@xxxxxxxxxxxxx> --- drivers/platform/x86/thinkpad_acpi.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c index 9c4df41687a3..477d63c49c04 100644 --- a/drivers/platform/x86/thinkpad_acpi.c +++ b/drivers/platform/x86/thinkpad_acpi.c @@ -6829,8 +6829,10 @@ static int __init tpacpi_query_bcl_levels(acpi_handle handle) list_for_each_entry(child, &device->children, node) { acpi_status status = acpi_evaluate_object(child->handle, "_BCL", NULL, &buffer); - if (ACPI_FAILURE(status)) + if (ACPI_FAILURE(status)) { + buffer.length = ACPI_ALLOCATE_BUFFER; continue; + } obj = (union acpi_object *)buffer.pointer; if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) { -- 2.28.0