USB resets

Greg KH gregkh at
Thu Apr 22 04:03:55 EDT 2021

On Thu, Apr 22, 2021 at 07:32:15AM +0000, Jorge Fernandez Monteagudo wrote:
> I've been able to stop the disconnecting loop.
> First I tried the usbcore.autosuspend=-1 guessing that an inactive period of time will send the device to some low power state, explaining the enumerating and disconnect loop with, but I had no luck.
> Then I force using the device with an udev rule running
> evtest --query $DEVNAME EV_KEY 0
> and the disconnection disappears. Maybe it's an error in the tobis touchscreen controller code??

Looks like the device is broken, sorry.  Again, the kernel can not cause
an electrical disconnection like this.

> I would like to test if the behavior changes in full speed instead of high speed. Is there some way to downgrade the EHCI speed to full speed?

Plug in a USB 1 bus?  if you can find such an old obsolete thing :)

good luck!

greg k-h

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