usbsdmux-configure make USB-SD-MUX Fast i2c errors

[sascgc]

Hi,

I just received new USB-SD-MUX fast boards. Revision: usb_sd_mux-S03-R02-V01-C00.

Seems that after using usbsdmux-configure with the USB-SD-MUX, and then doing usbsdmux /dev/usb-sd-mux/id-test01 host, it provokes i2c errors:

Traceback (most recent call last):
  File "/usr/bin/usbsdmux", line 10, in <module>
    sys.exit(main())
             ^^^^^^
  File "/usr/lib/python3/dist-packages/usbsdmux/__main__.py", line 105, in main
    print(ctl.get_mode())
          ^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/usbsdmux/usbsdmux.py", line 166, in get_mode
    val = self._pca.get_input_values()
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/usbsdmux/i2c_gpio.py", line 90, in get_input_values
    return self._read_register(self._register_inputPort)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/usbsdmux/i2c_gpio.py", line 56, in _read_register
    return self._usb.write_read_to(self._I2cAddr, [addr], 1)[0]
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/usbsdmux/usb2642.py", line 419, in write_read_to
    raise I2cTransactionFailed(
usbsdmux.usb2642.I2cTransactionFailed: SCSI-Transaction ended with status 2. I2C-Transaction has probably failed.

I tried with another USB-SD-MUX FASTwithout usbsdmux-configure and I can set the SD mux on host or dut.

Usbsdmux package: 24.01-1 and tried with the Main branch of usbsdmux either.
Distribution: 24.04.02 LTS
SD card: Using various, from U3, U1 and lower speed SD card used on old USB-SD-MUX (classic)
USB Cable: Less than 2m usb-c cable.

[SmithChart]

Hi,

thanks for your report. the usbsdmux-configure tool sets values in the EEPROM of the device. Depending on what you set there your devices now may behave differently. For normal use you should not need to use the usbsdmux-configure tool.

Do you remember what your last parameters to usbsdmux-configure were?
What is happening in dmesg -w while plugging in the USB-SD-Mux?

Good news are: It's totally possible to recover your device from this state and program it back to factory values:

• Read the serial number from the original box. It should be something like: 00048.NNNNN.
• Plug your USB-SD-Mux in and find the /dev/sg*-device for the USB-SD-Mux.
• Run usbsdmux-configure --productString "usb-sd-mux FAST" --manufacturerString "Linux Automation GmbH" --VID "0x0424" --PID "0x4041" --ScsiManufacturer "LinuxAutomation" --ScsiProduct "sdFST" /dev/sg<N> 00048.<NNNN>

If your device does not appear as /dev/sg* the configuration may be too broken. Find U3 on the side without the USB-Socket. That's the IC highlighted in green:

Then: Short all pins (1: SCL, 2: GND, 3: SDA) on the side with three pins while powering up the device.
(Make sure not to short any of the pins to the Resistors R15 and R16 as they are connected to 3.3V and may damage the Card Reader. )
This way the Card Reader won't be able to read the configuration from the EEPROM and it will start with factory defaults.

Let me know if this helps!

(Edit: Corrected side and designator (U10->U3of EEPROM.)