Bug#689368: Mouse and keyboard freeze on Ivy Bridge platform
On Thu, 4 Oct 2012, Sébastien Dinot wrote:
> Alan Stern a écrit :
> > The log file shows lots and lots of low-level communication errors.
> > They could be caused by bad cabling or by bad USB hardware in your
> > computer. It's unlikely that they were caused by the mouse or
> > keyboard, because the log shows errors for both of them starting at
> > exactly the same times.
>
> In my humble opinion, this issue is not caused by a bad USB hardware
> because I am encountering it with two different motherboards (MSI
> Z77A-G43 and ASUS P8Z77-V LX), both with an uptodate BIOS.
Maybe they have something in common. I don't know. All I can do is
explain to you what your kernel log indicates -- and it strongly
indicates a hardware error. Didn't you notice all those "detected
XactErr" lines in the log? There were more than 70000 of them!
> May be it is caused by a bad cabling but my mouse and my keyboard worked
> fine with my previous PC. They are connected to USB2 ports in both
> cases. But to clear up this point, I will try new mouse and keyboard.
>
> A last question: if it is a cable failure, why does it disappear
> temporarily when I unload then reload the module? I do not have deep
> experience and knowledge of hardware, may be there is a rational
> explanation to it.
That's a good point, and a cable failure indeed seems less likely than
some of the other possibilities (such as a failure of the internal
"rate-matching" hub).
One possible explanation is that an occasional noisy signal (caused by
a slightly faulty cable) triggers a bug in the internal hub, and that
bug causes all communication to fail until the hub is reset when you
reload the module.
> > You could try getting a USB-2 hub and attaching your mouse and
> > keyboard through the hub. That might help ... or it might not.
>
> Sorry, I do not understand the aim of this operation. Could you explain
> me it?
In addition to what Sarah said, it's possible that your problem is
related to the fact that the keyboard and mouse operate at low speed.
If you connected them through a hub then that hub would communicate
with the internal hub at high speed, not low speed.
Alan Stern
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