iMX8MN USB Serial Download failure with LIBUSB_ERROR_TIMEOUT

[1JoeK1]

Hello, we are bringing up a custom board with the iMX8M Nano.

Our custom board differs from the 8M Nano EVK in that we do not use USB-C.  Otherwise, the USB circuitry seems straightforward.  We run USB +5V through a 30k resistor to USB1_VBUS as was done on the EVK.

We use a Raspberry Pi for UUU - this setup works with the 8M Nano EVK.

dmesg shows the USB device is detected:

[26098.720244] usb 1-1.4: new high-speed USB device number 20 using dwc_otg
[26098.851605] usb 1-1.4: New USB device found, idVendor=1fc9, idProduct=013e, bcdDevice= 0.01
[26098.851631] usb 1-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[26098.851643] usb 1-1.4: Product: SE Blank 815
[26098.851655] usb 1-1.4: Manufacturer: NXP       SemiConductor Inc
[26098.880927] hid-generic 0003:1FC9:013E.0002: hiddev96,hidraw0: USB HID v1.10 Device [NXP       SemiConductor Inc  SE Blank 815  ] on usb-20980000.usb-1.4/input0

Serial Download fails almost immediately on our custom board.

pi@raspberrypi:~ $ sudo ./uuu-rpi-stretch flash_artemis_evk_8mn
uuu (Universal Update Utility) for nxp imx chips -- libuuu_1.4.43-4-g9aff92a

Success 0    Failure 1


1:14     1/ 1 [HID(W):LIBUSB_ERROR_TIMEOUT           ] SDPS: boot -f u-boot-imx8mn-evk-uuu.imx

Occasionally the error will be LIBUSB_ERROR_IO but it is usually the TIMEOUT error above.

The failure comes so early there is no UART output.  Can you give us some ideas on how to debug this?  Thank you,

Joe

[1JoeK1 · Accepted solution]

Aldo - We had changed the DDR bit order and needed to properly configure that using the DDR tool.  We can consider this closed now and I will post a new question if we have any additional bring-up questions.

[AldoG]

Hello,

Have you done changes disabling type-C to your code?
If not you may refer to the following:
https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/i-MX8MM-i-MX8MQ-USB2-0-Design-Without-US...

i.MX8MN is really similar to the i.MX8MM so you may use it as a reference. Also, since it is failing at such an early stage and it is a custom board, I would suggest to check the DDR by using the DDR tool:
https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/i-MX-8M-Family-DDR-Tool-Release/ta-p/110...

Best regards,
Aldo.

[1JoeK1]

Thank you for the ideas, Aldo - we will try these and update you here soon. -Joe