Re: 2.6.27: ehci bug with AMD 770nb/SB700 southbridge. usb lockup

[Greg KH <greg@kroah.com>]

On Thu, Oct 30, 2008 at 02:15:18AM +0100, Volker Armin Hemmann wrote:
> Hi,
> 
> I have a A770Crossfire board from Asrock.
> With kernel 2.6.26.X and 2.6.27.[1,2,3,4] I have the following problem that 
> makes usb mostly unusable.
> 
> I have a 4 port hub attached. A logitech mouse receiver is inserted into one 
> of its ports - it does not matter which one. Everything works fine.
> 
> I turn on an external enclosure, which is either attached to one of the 
> mainboards ports or the hub. Everything works for a couple of seconds. I mount 
> the cdrom/harddisk partition and start copying a file - or just wait a couple 
> of seconds.
> USB completly locks up. First the mouse, then a bit later the file transfer 
> (so one was started) stops. Turning of the enclosure does not help, remving 
> the receiver and reinserting it, does not help, not using the hub does not 
> help.
> Only thing that brings back USB:
> rmmod ehci_hcd
> modprobe ehci-hcd
> 
> rmmod and modprobe usb-storage does NOT help.
> 
> after that I get another couple of seconds until it locks up again.
> 
> If I modprobe ohci-hcd I get this:
> with 2.6.26 and the mouse at ohci, enclosure at ehci, everything works - but 
> gaming (with fglrx loaded) is impossible, since the mouse is extremly jerky 
> (shared interrupts).
> with 2.6.27 both mouse and enclose are driven by ohci - and copying works 
> without locking up. Trying to 'force' ehci for the enclosure makes it lockup 
> again.
> 
> This happens with kernel.org kernels+reiser4.

This chipset was known to have bugs in it, which I think we fixed
already.  I have a laptop with this chipset and it can sustain large
ammounts of USB data just fine with the 2.6.27 kernel series, so I
wonder if something is wrong with your usb disk drive?

I've added some AMD developers on the CC: who helped develop the last
fix for this chipset.  Libin, do you know of anything in the chipset
that would cause these problems?

thanks,

greg k-h