Hi Jan!

I'm sorry for not replying for such a long time after asking questions. :-)
>> I figured out, that reducing USBLP_BUF_SIZE (usb/class/usblp.c) form
>> 8192 to some smaller value, e.g. 4096 it works fine, but that's just a
>> workaround.
>>
>> USBLP_BUF_SIZE is used to "usb_buffer_alloc" (usb/core/usb.c) dma memory:
>>
>> >From usb.c:
>>     usb_buffer_alloc - allocate dma-consistent buffer for
>> URB_NO_xxx_DMA_MAP
>>
>> but here I'm out..
>>     
>
> Probably you're just suffering from domains without any I/O memory ranges
> assigned not being permitted to have multi-page contiguous memory ranges
> assigned? 
I added the usb-controllers as quirky devices, like xen told me to do:

    (usb
       (pci_ids
          ('1106:3038')
       )

       (pci_config_space_fields
          ('000000c0:2:00000000'
           '000000f0:2:00000000'
           '000000f8:2:00000000'
           '00000084:2:00000000')
         
       )
    )




> If not, do you force swiotlb on in the domain? And what resources
> does the USB HC require?
>   
Honestly I have no clue if I'm forcing it!
In the kernel-config I have "CONFIG_SWIOTLB=y"

Please see attaches "lspci"  for resource-view (or is there a better 
way, to see more information?)
I'm just using usb-controllers 0., 0.1 and 0.3 because 0.2 shares its 
irq with another device and is not working in domU.

I hope we can isolate the problem a bit more now.

Please contact me for more information. (I'm now online again and can 
answer much faster! :-) )


Thanks
Patrick