# Emobile USB issues

## monkeygirl

Hello. Quick question. After setting up my emobile modem (HUAWEI Mobile D21HW) I've had repeated problems with intermittent disconnections. The signal shows that the service is connected, but I cannot get online and I have to manually unplug the modem because poff -a does not disconnect the service.  I initially thought this was a network issue, but my kernel shows multiple instances of the following error:  

ehci_hcd  0000:00:1d.7 detected XactErr len 0/64 retry ... 

Furthermore, I do not have a problem using USB 1 ports and can stay connected for a long period of time on an older laptop, it is only on new my newer laptops which use USB 2 that this problem occurs. 

Is there anyway to troubleshoot the above error message, so that I can configure my modem/computer to prevent these errors? e.g., tricking one of my USB ports to be recognized only as a UHCI host controller? If there is more information I should paste here, please let me know.  Thanks for your time.

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## cyrillic

I'm not sure what that error message means, but it is easy enough to make your USB2 ports run at USB1 speeds for testing purposes.

Just add a line for ehci_hcd in /etc/modprobe.d/blacklist.conf so that the high speed driver won't be loaded when you boot.

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## monkeygirl

Thank you for your input. I'll recompile my kernel with the host controllers to load as modules and try your suggestion.

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