usb1-port1: disabled by hub (EMI?), re-enabling

Help and Support Raspberry Pi
1

2019-05-31_17h33_31
2019-05-31_17h33_311248×730 72.9 KB

—Setup—

  1. We are evaluating using Raspberry Pi Compute Module CM3.
  2. USB-HUB and USB-UART are boarded on the IO board.
  3. USB-HUB is working in Self-power mode.
  4. VBUS-detect of USB-HUB uses the same 3.3V power supply as CM3.
  5. Two LTE modules are connected to USB-HUB via USB-SERIAL and each LTE module takes 2A

—Protocol—

AT commands

—Problem----

The LTE modules which are connected to USB-HUB are disconnecting.This problem occurs only sometimes not always

Following are kernel Logs.

Kerenl log:
19:47:58 raspberrypi kernel: [ 9301.001438] usb usb1-port1: disabled by hub (EMI?), re-enabling…
19:47:58 raspberrypi kernel: [ 9301.001457] usb 1-1: USB disconnect, device number 11
19:47:58 raspberrypi kernel: [ 9301.001463] usb 1-1.1: USB disconnect, device number 12
19:47:58 raspberrypi kernel: [ 9301.001668] ftdi_sio ttyUSB2: error from flowcontrol urb
19:47:58 raspberrypi kernel: [ 9301.001872] ftdi_sio ttyUSB2: FTDI USB Serial Device converter now disconnected from ttyUSB2
19:47:58 raspberrypi kernel: [ 9301.001906] ftdi_sio 1-1.1:1.0: device disconnected
19:47:58 raspberrypi kernel: [ 9301.002107] ftdi_sio ttyUSB3: error from flowcontrol urb
19:47:58 raspberrypi kernel: [ 9301.003371] ftdi_sio ttyUSB3: FTDI USB Serial Device converter now disconnected from ttyUSB3
19:47:58 raspberrypi kernel: [ 9301.003429] ftdi_sio 1-1.1:1.1: device disconnected
19:47:58 raspberrypi kernel: [ 9301.010150] ftdi_sio ttyUSB4: FTDI USB Serial Device converter now disconnected from ttyUSB4
19:47:58 raspberrypi kernel: [ 9301.010212] ftdi_sio 1-1.1:1.2: device disconnected
19:47:58 raspberrypi kernel: [ 9301.010430] ftdi_sio ttyUSB5: error from flowcontrol urb
19:47:58 raspberrypi kernel: [ 9301.018012] ftdi_sio ttyUSB5: FTDI USB Serial Device converter now disconnected from ttyUSB5

—Question—

Any investigation method and solution?

2

Have you tried if the problem also happens with Raspbian?

3

Almost certain to by EMI especially if the 5V 3.5A is a SMPSU.

In your setup line 5 you have two LTE modules each taking (up to 2 amps)
so your PSU is inadequate.

You either need a larger PSU or a powered USB hub that can deliver at least
2 amps to each of its USB ports.

The kernel message regarding (EMI ?) is a good guess, but I had terrible radio
interference frpm a SMPSU re-radiating interference across my LAN cables.
Solutions here:
A metal screen SMPSU or a linear PSU.

The problem with many power supplies is that they never quite deliver the rated
load. In your case you’re trying to draw too much current tan your PSU can deliver
so something is going to shut down.

You could also probably get around this if you used 1 LTE module as this is much
less load requirements.
Hope that helps.