BBAI USB-C only enumerates as high speed device with cable in one orientation

[nick.g...@gmail.com]

Hello,

I have noticed that my BBAI Rev A1, when connected to a PC, will enumerate as a high-speed USB device with the USB-C connector in one orientation, and a Super-Speed device with the connector oriented in the other direction (simply flipped upside down). I have reproduced this across several software revisions including the production emmc image: http://debian.beagleboard.org/images/am57xx-eMMC-flasher-debian-9.9-lxqt-armhf-2019-08-03-4gb.img.xz

I checked the https://github.com/beagleboard/beaglebone-ai/wiki/System-Reference-Manual#board-changes page and did not see any changes related to USB in any of the newer revisions. I was wondering if there are others who also have experienced this issue, or if it could be isolated to my specific board. I have reproduced the issue with several different USB-C cables including a USB A->USB-C and USB-C -> USB-C cable.

First orientation:

Nov  6 13:54:36 lnx-nickg kernel: [606956.216954] usb 1-5: new high-speed USB device number 48 using xhci_hcd
Nov  6 13:54:36 lnx-nickg kernel: [606956.346011] usb 1-5: New USB device found, idVendor=1d6b, idProduct=0104
Nov  6 13:54:36 lnx-nickg kernel: [606956.346013] usb 1-5: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Nov  6 13:54:36 lnx-nickg kernel: [606956.346015] usb 1-5: Product: BeagleBone
Nov  6 13:54:36 lnx-nickg kernel: [606956.346017] usb 1-5: Manufacturer: BeagleBoard.org
Nov  6 13:54:36 lnx-nickg kernel: [606956.346018] usb 1-5: SerialNumber: 1234BBBK5678 

Nov  6 13:54:36 lnx-nickg kernel: [606956.347593] usb-storage 1-5:1.2: USB Mass Storage device detected 

...

Second orientation:

Nov  6 14:04:53 lnx-nickg kernel: [607573.545068] usb 2-5: new SuperSpeed USB device number 32 using xhci_hcd
Nov  6 14:04:53 lnx-nickg kernel: [607573.562236] usb 2-5: New USB device found, idVendor=1d6b, idProduct=0104
Nov  6 14:04:53 lnx-nickg kernel: [607573.562246] usb 2-5: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Nov  6 14:04:53 lnx-nickg kernel: [607573.562252] usb 2-5: Product: BeagleBone
Nov  6 14:04:53 lnx-nickg kernel: [607573.562258] usb 2-5: Manufacturer: BeagleBoard.org
Nov  6 14:04:53 lnx-nickg kernel: [607573.562263] usb 2-5: SerialNumber: 1234BBBK5678
Nov  6 14:04:53 lnx-nickg kernel: [607573.567404] usb-storage 2-5:1.2: USB Mass Storage device detected

...

[Andrew P. Lentvorski]

I haven't checked the Bill of Materials, but if U22 (the TUSB322IRWBR USB-C control chip) is populated along with R533 and R534, then the board is out of spec for USB-C on the CC lines.