# strange usb related logs, explanation (and solution !) pleaz

## brain salad surgery

How to explain and avoid this (2.6.34-gentoo-r1):

[34903.835590] usb 2-1.1: link qh1-0601/ffff8800716b9080 start 0 [1/2 us]

[34907.894811] usb 2-1: clear tt buffer port 1, a6 ep3 t80408d82

[34907.894847] usb 2-1.1: unlink qh1-0601/ffff8800716b9080 start 0 [1/2 us]

[34937.842083] ehci_hcd 0000:00:1d.0: reused qh ffff8800716b9080 schedule

[34937.842090] usb 2-1.1: link qh1-0601/ffff8800716b9080 start 0 [1/2 us]

[34937.860849] ehci_hcd 0000:00:1d.0: detected XactErr len 0/10 retry 1

[34937.861615] usb 2-1.1: unlink qh1-0601/ffff8800716b9080 start 0 [1/2 us]

[34937.861680] ehci_hcd 0000:00:1d.0: reused qh ffff8800716b9080 schedule

[34937.861685] usb 2-1.1: link qh1-0601/ffff8800716b9080 start 0 [1/2 us]

[34941.441797] ehci_hcd 0000:00:1d.0: detected XactErr len 0/10 retry 1

[34941.442566] usb 2-1.1: unlink qh1-0601/ffff8800716b9080 start 0 [1/2 us]

[34941.442631] ehci_hcd 0000:00:1d.0: reused qh ffff8800716b9080 schedule

[34941.442636] usb 2-1.1: link qh1-0601/ffff8800716b9080 start 0 [1/2 us]

[34941.901953] usb 2-1: clear tt buffer port 1, a6 ep3 t80408d82

[34941.901980] usb 2-1.1: unlink qh1-0601/ffff8800716b9080 start 0 [1/2 us]

I try to use a script to read from a temperature sensor kit

using a pl2303 usb to serial converter (the microcrontoller is usually

directly plugged into the serial port but I don't have any).

Works anyways, but needs regular resets and it produces the logs above.

I get tons and tons of this, every 3 seconds when the script's running

Sometimes there are timeout errors.

When the microcontroller's connection is not resetted, it hangs.

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## NeddySeagoon

brain salad surgery,

It looks like you have some USB debug on in your kernel. Rebuild your kernel with all debug options off. Unless you need to debug any parts of the kernel.

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## brain salad surgery

ok thanks,

so all those logs related to problems I see with timeouts using pl2303 based usb to serial converters ?

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