Re: Strange behaviour on PCEngines APU2

[Greg Troxel <gdt%lexort.com@localhost>]

Staffan Thomén <duck%shangtai.net@localhost> writes:

> Anyway, I found what was causing the issue, if not how. I have a
> telldus tellstick 433MHz "home automation" controller connected via
> USB to the system, and removing it completely cleared the problem. The
> APU has been running for several days now without issue.

I conclude that  you have found a bug (not sure where yet) and it's
overwhelmingly likely this isn't about your apu2.

> Normally the tellstick would attach as a uftdi device with an ucom,
> but because the controlling daemon uses libftdi I've disabled those
> and it's attached as an ugen device.

Slightly surprising that the daemon doesn't just use a serial port.
(aoetec zstick seems to just be serial)

> There was also a problem communicating with it when it attached using
> ehci, disabling ehci made it connect through an uhub attached to xhci
> and it started to work. Apparently something isn't working right
> though, but I don't know any knobs to twiddle here.

Are you sure you didn't get that backwards?  ehci is USB2, and xhci is
USB3.  Is the tellstick a USB3 device, or USB2, or ?

> The device was working flawlessly on the soekris.

Which I'm pretty sure has only USB2.  usb dmesg from a net6501:
  usb0 at ohci0: USB revision 1.0
  usb1 at ohci1: USB revision 1.0
  usb2 at ohci2: USB revision 1.0
  usb3 at ehci0: USB revision 2.0
  usb4 at ohci3: USB revision 1.0
  usb5 at ohci4: USB revision 1.0
  usb6 at ohci5: USB revision 1.0
  usb7 at ehci1: USB revision 2.0

whereas apu2d4

  usb0 at xhci0: USB revision 3.0
  usb1 at xhci0: USB revision 2.0
  usb2 at ehci0: USB revision 2.0


Looking at my apu2, it seems to have xhci and ehci and no ohci, so I
wonder if xhci now does USB1/2/3, and your device is USB1.

I would be looking at trying to add attachment quirks so that the device
is not attached by the USB controller that causes problems, which is
like removing it for this devive, but not in general.