Unrecognized USB occasionally

We use the jetson nano core board. During repeated startup, the USB cannot be recognized occasionally. The USB chip model we use is VL817. What may be the reason? The first picture is normal, and the second The picture is an abnormal situation, and the third picture is the print information of the kernel at startup

syslog (1.2 MB)

Hello @tiancai1234,

what pins/ports are you connecting to the hub? And what type of connector is being used?

The USB HUB chip used is VIA VL817-Q7, the host side connection pins in the schematic diagram are as follows, the USB1_P (117pin) of the core board of the NVIDIA NANO EMMC version is connected to the USB1_P (53pin) of VIA VL817-Q7, and the USB1_N (115pin) of the core board Connect to USB1_N (54pin) of HUB VL817-Q7, SSRX0_P (168pin) of the core board is connected to SSRX0_P (51pin) of HUB VL817-Q7, SSRX0_N (166pin) of the core board is connected to SSRX0_N (50pin) of HUB VL817-Q7, The SSTX0_P (163pin) of the core board is connected to the SSTX0_P (48pin) of the HUB VL817-Q7 through a 100nF capacitor, and the SSTX0_N (161pin) of the core board is connected to the SSTX0_N (47pin) of the HUB VL817-Q7 through a 100nF capacitor. The downstream port of VL817-Q7 is 4port USB3.0.

Hi @tiancai1234,

I see inconsistencies regarding the pins assignment. Please review the Table 10 in the Jetson Xavier NX Datasheet. Another good reference is the reference design in Figure 5 -1 in Jetson Xavier NX Design Guide.

Hello, what are the specific inconsistencies, we designed according to the manual you said. In addition, we also found that when there is a problem, the USB3.0 device can be recognized, but the 2.0 device cannot be recognized

Hi @tiancai1234 pins 161/163 are USBSS_RX while pins 168/166 are USBSS_TX. I am assuming this might be associated to the firmware of the hub you adopted. I can still review your device tree and make sure the USB controller properties are coherent. If you wish so, please share the DTB. Also, what types of connectors are you using?

Our mirror uses the official L4T R32.5.1,The USB HUB chip used is VIA VL817-Q7