Arch Linux

marble

Member

Registered: 2016-02-05

Posts: 9

[SOLVED] CP210x (CP2102) USB ehci problem

Hello,
I want to use a Silicon Labs CP2102 USB to UART converter.
The converter works fine wit my friends Mac, but my system (Arch Linux on Lenovo x220T) can't use it.
I just updated the whole systen (pacman -Syu).
uname -r prints 4.4.1-2-ARCH
When I plug in the device dmesg prints

[ 2519.724218] usb 2-1.1: new full-speed USB device number 18 using ehci-pci
[ 2519.790922] usb 2-1.1: device descriptor read/64, error -32
[ 2519.960923] usb 2-1.1: device descriptor read/64, error -32
[ 2520.130861] usb 2-1.1: new full-speed USB device number 19 using ehci-pci
[ 2520.197590] usb 2-1.1: device descriptor read/64, error -32
[ 2520.367563] usb 2-1.1: device descriptor read/64, error -32
[ 2520.537596] usb 2-1.1: new full-speed USB device number 20 using ehci-pci
[ 2520.944223] usb 2-1.1: device not accepting address 20, error -32
[ 2521.010897] usb 2-1.1: new full-speed USB device number 21 using ehci-pci
[ 2521.417520] usb 2-1.1: device not accepting address 21, error -32
[ 2521.417695] usb 2-1-port1: unable to enumerate USB device

I googled for an hour now and found no problem solving solution.

Last edited by marble (2016-02-05 10:27:42)

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,654

Re: [SOLVED] CP210x (CP2102) USB ehci problem

Is it on a cable? or does it plug straight in?  Are you connecting it to a 1.1, 2.0 or 3.0 capable interface.  It looks like 2.0

That it enumerates but then fails to read the device descriptor is a bad sign
What kind of computer is it?

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marble

Member

Registered: 2016-02-05

Posts: 9

Re: [SOLVED] CP210x (CP2102) USB ehci problem

It's a Lenovo X220T with Intel Core i7. There is no USB cable involved.
I tried every accessible USB port. Every port is USB 2.0.

Last edited by marble (2016-02-05 04:08:02)

marble

Member

Registered: 2016-02-05

Posts: 9

Re: [SOLVED] CP210x (CP2102) USB ehci problem

New info:
The device can be enumerated when I plug in an USB hub and then plug the CP2102 into the hub.

But that solution is not very satisfying...

marble

Member

Registered: 2016-02-05

Posts: 9

Re: [SOLVED] CP210x (CP2102) USB ehci problem

OK,
obviously the reason was that i've set the 3v3 jumper on the device.
A friend said that certain hardware can handle less precise signals and other not.

x33a

Forum Fellow

Registered: 2009-08-15

Posts: 4,587

Re: [SOLVED] CP210x (CP2102) USB ehci problem

@marble, so it's solved now? If so, then please mark the thread as solved.