Hi!To SCI handler itself, I don't think keyboard controller will be touched. But SCI handler could evaluate some AML method which could touch keyboard controller. --LumingWould that be a bug in AML method? Or how is keyboard-controller access locked between OS and ACPI? PavelDoes it mean the overhead of SCI interrupt was not the root cause of this issue. --LumingIt certainly looks so. Is it possible that SCI handler touches keyboard controller?