deloptes wrote:
Unfortunately, trying different USB ports does not make any difference,
as
all my external USB ports belong to the same controller. Would like to
try
your other suggestion, unloading xhci_hcd and let the system fall back
to
ehci_hcd. How do I do that? I tried blacklisting xhci_hcd, following
the
instructions in the Debian Kernel Manual Chapter 6. When I rebooted,
xhci_hcd loaded anyhow.
sudo rmmod xhci_hcd ?
Unfortunately, it is not that simple. The initial challenge is rmmod
refuses to remove xhci_hcd, saying it is already in use. I figured out
that challenge. First you have to remove xhci_pci, then it will let you
remove xhci_hcd. The bigger challenge is, removing the xhci modules leaves
all the external USB ports disabled. I was hoping the system would fall
back to using ehci_hcd for those ports, but no such luck. Maybe I need to
reinitialize something?