[Bug 88746] Re: ehci_hcd module causes I/O errors in USB 2.0 devices

[Martin Lubich]

I am using kubuntu 8.04.1 and just recently upgraded my computer to a
amd770/sb600 based system (Phenom9750, 8GB, 64bit).

I never had any problems with my old setup (AMD Athlon 1500+, VIA chipset). But after upgrading I started experiencing the above mentioned behaviour regarding usb 2.0 devices. 
After a lot of investigation and finding the problem described in a lot of places ( but not very coherently) including several posts on the lkml I think this is partly a hardware related problem.

Until now, there is no REAL solution to this problem. All the solutions
provided here or at other places are solutions which may work on a
particular setup, but surely not for all.

I have now found the solution for my setup, which seems to confirm the hardware relation. I also had the behaviour, that as soon as a hub is attached , the problems started to occur. As this does not hint at a software problem I increased the voltage for my southbridge (sb600) by 0.1 volts, which my bios conveniently offers. This was done with the hypothesis, that the controller might operate electrically in an undefined area, where external devices may trigger a complete failure of the controller (which seems to be the case in all the reports).
Well, the increase in voltage did the trick for me. But, again, this is a fix for my setup. I just adds evidence that here is not a mere software problem at hand.

The interesting part would be now, to investigate the kernel changes in
the 2.6 series which actually triggers this behaviour.

-- 
ehci_hcd module causes I/O errors in USB 2.0 devices
https://bugs.launchpad.net/bugs/88746
You received this bug notification because you are a member of Kernel
Bugs, which is subscribed to Linux.