Tool/software:
Our AM62x board has both USB ports enabled — usb0 is connected to a USB port, and usb1 is connected to a touchscreen.
During normal boot, there will be two “USB bus registered” messages.
[ 1.279734] xhci-hcd xhci-hcd.0.auto: xHCI Host Controller [ 1.285297] xhci-hcd xhci-hcd.0.auto: new USB bus registered, assigned bus number 1 [ 1.293087] xhci-hcd xhci-hcd.0.auto: USB3 root hub has no ports [ 1.299092] xhci-hcd xhci-hcd.0.auto: hcc params 0x0258fe6d hci version 0x110 quirks 0x0000000000010010 [ 1.308537] xhci-hcd xhci-hcd.0.auto: irq 243, io mem 0x31000000 [ 1.314823] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002, bcdDevice= 6.01 [ 1.323082] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 1.330296] usb usb1: Product: xHCI Host Controller [ 1.335168] usb usb1: Manufacturer: Linux 6.1.33 xhci-hcd [ 1.340594] usb usb1: SerialNumber: xhci-hcd.0.auto [ 1.345952] hub 1-0:1.0: USB hub found [ 1.349764] hub 1-0:1.0: 1 port detected [ 1.355637] xhci-hcd xhci-hcd.1.auto: xHCI Host Controller [ 1.361243] xhci-hcd xhci-hcd.1.auto: new USB bus registered, assigned bus number 2 [ 1.369028] xhci-hcd xhci-hcd.1.auto: USB3 root hub has no ports [ 1.375032] xhci-hcd xhci-hcd.1.auto: hcc params 0x0258fe6d hci version 0x110 quirks 0x0000000000010010 [ 1.384610] xhci-hcd xhci-hcd.1.auto: irq 244, io mem 0x31100000 [ 1.390864] usb usb2: New USB device found, idVendor=1d6b, idProduct=0002, bcdDevice= 6.01 [ 1.399222] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 1.406438] usb usb2: Product: xHCI Host Controller [ 1.411315] usb usb2: Manufacturer: Linux 6.1.33 xhci-hcd [ 1.416814] usb usb2: SerialNumber: xhci-hcd.1.auto [ 1.422161] hub 2-0:1.0: USB hub found [ 1.425967] hub 2-0:1.0: 1 port detected [ 1.431560] cpufreq: cpufreq_online: CPU0: Running at unlisted initial frequency: 1200000 KHz, changing to: 1250000 KHz [ 1.444462] mmc0: CQHCI version 5.10 [ 1.450244] mmc1: CQHCI version 5.10
However, sometimes during boot usb0 fails to be detected while usb1 works fine. At the failure point, the system pauses for about 14 seconds. Details are shown below.
After this happens, even if we reboot, the new system still shows a USB probe failure — only a full power-off and restart will clear the problem.
[ 1.279704] xhci-hcd xhci-hcd.0.auto: xHCI Host Controller [ 1.285264] xhci-hcd xhci-hcd.0.auto: new USB bus registered, assigned bus number 1 [ 15.549896] xhci-hcd xhci-hcd.0.auto: can't setup: -110 [ 15.555130] xhci-hcd xhci-hcd.0.auto: USB bus 1 deregistered [ 15.560805] xhci-hcd: probe of xhci-hcd.0.auto failed with error -110 [ 15.569035] xhci-hcd xhci-hcd.1.auto: xHCI Host Controller [ 15.574568] xhci-hcd xhci-hcd.1.auto: new USB bus registered, assigned bus number 1 [ 15.582357] xhci-hcd xhci-hcd.1.auto: USB3 root hub has no ports [ 15.588361] xhci-hcd xhci-hcd.1.auto: hcc params 0x0258fe6d hci version 0x110 quirks 0x0000000000010010 [ 15.597802] xhci-hcd xhci-hcd.1.auto: irq 244, io mem 0x31100000 [ 15.604119] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002, bcdDevice= 6.01 [ 15.612378] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 15.619591] usb usb1: Product: xHCI Host Controller [ 15.624464] usb usb1: Manufacturer: Linux 6.1.33 xhci-hcd [ 15.629856] usb usb1: SerialNumber: xhci-hcd.1.auto [ 15.635212] hub 1-0:1.0: USB hub found [ 15.639013] hub 1-0:1.0: 1 port detected [ 15.644578] cpufreq: cpufreq_online: CPU0: Running at unlisted initial frequency: 1200000 KHz, changing to: 1250000 KHz [ 15.657400] mmc0: CQHCI version 5.10 [ 15.663077] mmc1: CQHCI version 5.10
In our hardware design, the 5 V for usb0 is controlled by a GPIO enable signal, and I have already enabled it in U-Boot.
We have two 10 pF filter capacitors on our USB line. Could this affect the USB probe?
What else could cause this problem? thanks
