2 ms·

This. Apple does something similar if you try to pull too much power

• gumby 7y ago
  Only in the power case -- how can it know that you didn't intend to use USB 1? It wouldn't be able to tell what the other side is capable of in that case, hence the fallback.
  • bonzini 7y ago
    It could know via USB descriptors, and match the device capabilities from the descriptors against what the cable allows.