[SeaBIOS] SeaBIOS recognising USB 3.0 on boot works - partly

Kevin O'Connor kevin at koconnor.net
Fri Dec 18 23:44:11 CET 2015

On Fri, Dec 18, 2015 at 08:12:22PM +0000, edward wandasiewicz wrote:
> As requested.

Thanks.  It appears this particular device is being fully detected as
a USB2 device (connection is detected, address is assigned, drive
configuration is downloaded, and the drive is registered internally)
before the controller/device negotiate a USB3 connection.  Once the
device is recognized as USB3, the controller disconnects it from USB2,
but by that point SeaBIOS has already fully registered it and isn't
even checking the connection status.  The device is then fully
detected as a USB3 device, which is why the duplicate shows up.

I don't have a good way to fix that.  It's possible to add a delay to
USB2 device detection on XHCI controllers to try and make sure they
are really USB2 devices, but that isn't a great solution as it adds an
unnecessary delay to all other drives (that behave properly).

In some of your other emails, you mention type-c cables and different
behavior with different cables.  The cabling choice has no impact on
the software, so I wonder if one of the cables you have (or
combination of cables) isn't fully insulated and if it could be
causing a delay in USB3 negotiation.  If it's possible to fix this
with a different cable, that may be the easiest solution.


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