USB3 mostly broken; fixed in linux kernel 3.4.10

[Charles Evans <cvevans@users.sourceforge.net>]

I just got an HP computer with an A10 CPU and USB3.
I had numerous failures, with USB3 ports vanishing while in use;
they only reappeared after a cold reset.
Once a port vanished during a long write;
 the drive light kept blinking for hours - until cold reset by reboot.

If I use the USB3 drives only on USB2 ports, everything is fine.
I can even use the USB3 ports, but only for USB2 devices.

I found this:

commit 1aac2e73a8af6ce1cd6e938967dd17e2c8d38994
xhci: Fix bug after deq ptr set to link TRB.
https://www.kernel.org/pub/linux/kernel/v3.0/ChangeLog-3.4.10

    This patch fixes a particularly nasty bug that was revealed by the ring
    expansion patches.  The bug has been present since the very beginning of
    the xHCI driver history, and could have caused general protection faults
    from bad memory accesses.

dmesg confirms this bug bit me, and often (esp. with K704 on a USB3 port).
Simple tests of one USB3 device with one thread accessing it often work
(on simple devices with no NCQ?). 
I hope you can do a new boot disk with a new kernel (if that will work).

Thanks!
Charles