[gentoo-user] USB serial adapter not working

[gentoo-user] USB serial adapter not working

[Petric Frank]

Hello,

i own a USB docking station which also contains a serial connector.

The host will do USB 2.0 (kernel module ehci-hcd) and detects the PL2303 
serial port properly. It loads the appropiate kernel module, but at the end 
it fails somehow with the following message:
---------------- cut --------------------
pl2303 ttyUSB0: pl2303_open - failed submitting interrupt urb, error -28
---------------- cut --------------------

As result the device /dev/ttyUSB0 is allocated by udev, but not working.

After some tests i got a work around. I have to unload the kernel module 
ehci-hcd. Due uhci-hcd remains loaded the device works in USB 1.1 mode. Here 
the serial port works properly.

Is there a fix the keep me from unloading the kernel module every time i want 
to use the serial port ?
For example by directing the system to always bind the serial port to uhci-hcd 
(USB 1.1). Or better by a fix for ehci-hcd/pl2303 kernel.

My system is Gentoo 2007.0, i386 and x86_64.

lsusb tells (limited to the docking station):
---------------- cut --------------------
Bus 005 Device 009: ID 067b:0000 Prolific Technology, Inc. PL2301 USB-USB 
Bridge
Bus 005 Device 006: ID 067b:2305 Prolific Technology, Inc. PL2305 Parallel 
Port
Bus 005 Device 008: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port
Bus 005 Device 007: ID 0d3d:0001 Tangtop Technology Co., Ltd
Bus 005 Device 005: ID 05e3:0604 Genesys Logic, Inc. USB 1.1 Hub
Bus 005 Device 004: ID 1631:6200
Bus 005 Device 003: ID 0409:0058 NEC Corp. HighSpeed Hub
---------------- cut --------------------

regards
  Petric
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