Measured on an ASRock Intel Arc B580 Steel Legend, which uses this same
packet: holding everything else fixed and stepping data[5] through 0xFF,
0x40 and 0x00 dims the zone progressively and turns it off at zero, while
data[4] does not change brightness. So data[4] is the effect speed and
data[5] is the brightness, the other way around from what the comments
said. The bytes written are unchanged, this only fixes the labels.
Every other ASRock controller shuts the device thread down before deleting
the controller. This one did not, so tearing it down logs
Device thread still active in base class destructor, ensure Shutdown()
was called from inherited destructor
on every exit. Seen on an ASRock Intel Arc B580 Steel Legend, but the file
is shared with the Radeon Steel Legend and Taichi cards.
Victor Ferreira