Hey,
I got a CEM40 and overall the mount works fine on linux but there are some issues. While I am able to run a session, and I was even able to run a full night with limited issues, I have had the whole USB subsystem crash on my, and have found to be able to do is consistently.
I am using the 2021 version of the CEM40 with a single USB cable which connects to a USB2.0 HUB, the CEM40 itself, and the iPolar. It only works when connected to my powered USB hub, connecting to the USB3.0 or 2.0 ports directly does not work.
I am able to work for a while but then sometimes the USB subsystem will crash, and all USB devices disconnect. I have run it with just the HUB + the CEM40 and have it crash, and I ran the HUB for 6 months with zero issues before getting the CEM.
When the subsystem crashes all devices except the root hubs will no longer be visible with lsusb, and dmesg reports the following :
[ 6035.747938] usb 1-1.2: new high-speed USB device number 3 using xhci_hcd
[ 6035.882081] usb 1-1.2: New USB device found, idVendor=05e3, idProduct=0610, bcdDevice=92.26
[ 6035.882098] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 6035.882111] usb 1-1.2: Product: USB2.0 Hub
[ 6035.882125] usb 1-1.2: Manufacturer: GenesysLogic
[ 6035.988356] usb 2-2.1: new SuperSpeed Gen 1 USB device number 3 using xhci_hcd
[ 6036.021349] usb 2-2.1: New USB device found, idVendor=05e3, idProduct=0616, bcdDevice=92.26
[ 6036.021364] usb 2-2.1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 6036.021375] usb 2-2.1: Product: USB3.0 Hub
[ 6036.021386] usb 2-2.1: Manufacturer: GenesysLogic
[ 6036.207930] usb 1-1.2.1: new high-speed USB device number 4 using xhci_hcd
[ 6036.341031] usb 1-1.2.1: New USB device found, idVendor=05e3, idProduct=0610, bcdDevice=92.26
[ 6036.341055] usb 1-1.2.1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 6036.341073] usb 1-1.2.1: Product: USB2.0 Hub
[ 6036.341090] usb 1-1.2.1: Manufacturer: GenesysLogic
[ 6036.677955] usb 1-1.2.1.1: new high-speed USB device number 5 using xhci_hcd
[ 6036.808640] usb 1-1.2.1.1: New USB device found, idVendor=1a40, idProduct=0101, bcdDevice= 1.00
[ 6036.808662] usb 1-1.2.1.1: New USB device strings: Mfr=0, Product=1, SerialNumber=0
[ 6036.808679] usb 1-1.2.1.1: Product: USB 2.0 Hub [MTT]
[ 6037.237932] usb 1-1.2.1.1.3: new high-speed USB device number 6 using xhci_hcd
[ 6037.506719] usb 1-1.2.1.1.3: New USB device found, idVendor=1233, idProduct=1455, bcdDevice= 1.00
[ 6037.506729] usb 1-1.2.1.1.3: New USB device strings: Mfr=2, Product=1, SerialNumber=0
[ 6037.506736] usb 1-1.2.1.1.3: Product: iOptron iPolar
[ 6037.506743] usb 1-1.2.1.1.3: Manufacturer: iOptron iPolar
[ 6037.564768] input: iOptron iPolar: iOptron iPolar as /devices/platform/scb/fd500000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0/usb1/1-1/1-1.2/1-1.2.1/1-1.2.1.1/1-1.2.1.1.3/1-1.2.1.1.3:1.0/input/input3
[ 6037.767969] usb 1-1.2.1.1.4: new full-speed USB device number 7 using xhci_hcd
[ 6038.015998] usb 1-1.2.1.1.4: New USB device found, idVendor=0403, idProduct=6015, bcdDevice=10.00
[ 6038.016016] usb 1-1.2.1.1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 6038.016029] usb 1-1.2.1.1.4: Product: FT230X Basic UART
[ 6038.016043] usb 1-1.2.1.1.4: Manufacturer: FTDI
[ 6038.016055] usb 1-1.2.1.1.4: SerialNumber: D3091EXI
[ 6038.026066] usb 1-1.2.1.1.4: Detected FT-X
[ 6038.031436] usb 1-1.2.1.1.4: FTDI USB Serial Device converter now attached to ttyUSB0
[ 6201.049896] usb 1-1.2: USB disconnect, device number 3
[ 6201.049921] usb 1-1.2.1: USB disconnect, device number 4
[ 6201.049942] usb 1-1.2.1.1: USB disconnect, device number 5
[ 6201.049962] usb 1-1.2.1.1.3: USB disconnect, device number 6
[ 6201.157294] usb 1-1.2.1.1.4: USB disconnect, device number 7
[ 6201.460561] usb 1-1.2: new high-speed USB device number 8 using xhci_hcd
[ 6201.560765] usb 1-1.2: device descriptor read/64, error -71
[ 6201.780821] usb 1-1.2: device descriptor read/64, error -71
[ 6202.000620] usb 1-1.2: new high-speed USB device number 9 using xhci_hcd
[ 6202.100845] usb 1-1.2: device descriptor read/64, error -71
[ 6202.320842] usb 1-1.2: device descriptor read/64, error -71
[ 6202.441260] usb 1-1-port2: attempt power cycle
USB disconnect, device number 3 is the start of the error.
I can run the following commands twice to get the devices to re-connect :
sudo sh -c "echo 1 > /sys/bus/pci/devices/0000:00:00.0/remove"
sudo sh -c "echo 1 > /sys/bus/pci/rescan"
I can also get it to crash 100% of the time when trying to use the iPolar driver, or even when trying to stream from the iPolar in vlc using the video4linux drivers, so I wonder if it is a compatibility issue.
I have ordered a usb multimeter to test if this is an issue with the HUB shutting the iPolar down for drawing too much power, but wanted to ask if anyone else has had this issue?