We have developed one more new custom carrier board with iMX 8M Plus SOM Module.
As a USB Hub, we have used 4 port, USB5744T-I/2G and 3 ports connected to USB to Quad UART IC (FT4232HL-REEL) and 4 th port connected to USB 3.0 Connector.
When the board is booting up, we are getting a message like “[ 129.221836] usb usb4: We don’t know the algorithms for LPM for this host, disabling LPM.
[ 129.230500] hub 4-0:1.0: USB hub found
[ 129.234324] hub 4-0:1.0: 1 port detected
[ 129.238723] xhci-hcd xhci-hcd.2.auto: remove, state 1
[ 129.243832] usb usb4: USB disconnect, device number 1
[ 129.249412] xhci-hcd xhci-hcd.2.auto: USB bus 4 deregistered
[ 129.255146] xhci-hcd xhci-hcd.2.auto: remove, state 1
[ 129.260238] usb usb3: USB disconnect, device number 1
[ 129.381196] xhci-hcd xhci-hcd.2.auto: USB bus 3 deregistered
[ 129.668112] xhci-hcd xhci-hcd.2.auto: xHCI Host Controller
[ 129.673696] xhci-hcd xhci-hcd.2.auto: new USB bus registered, assigned bus number 3
[ 129.681751] xhci-hcd xhci-hcd.2.auto: hcc params 0x0220fe65 hci version 0x110 quirks 0x0000002001010010
[ 129.691201] xhci-hcd xhci-hcd.2.auto: irq 77, io mem 0x38100000
[ 129.697245] xhci-hcd xhci-hcd.2.auto: xHCI Host Controller
[ 129.702761] xhci-hcd xhci-hcd.2.auto: new USB bus registered, assigned bus number 4
[ 129.710450] xhci-hcd xhci-hcd.2.auto: Host supports USB 3.0 SuperSpeed
[ 129.717563] hub 3-0:1.0: USB hub found
[ 129.721384] hub 3-0:1.0: 1 port detected”
and it’s continuously repeating it. Hardware side, all serial ports (usb to quad uart) and USB port (last port) also working fine. but why it’s continuously displaying this message on booting.
Hi, I’m the Toradex AI Assistant. The Toradex Support team will follow up with you shortly!
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Hello,
Thank you for reaching out with your question about the USB messages during boot on your custom carrier board with the iMX 8M Plus SOM module. It sounds like you’re encountering a common issue related to USB power management or hub configuration. Here are some steps you can take to address this:
USB Hub Compatibility: Verify that the USB5744T-I/2G hub is fully compatible with the iMX 8M Plus SOM. Ensure that the hub’s firmware and configuration are up-to-date and compatible with your Linux kernel version.
Power Management Settings: The message about “disabling LPM” (Link Power Management) suggests that the system might not support certain power management features. You could try disabling USB power management in the kernel configuration or through boot parameters to see if this resolves the issue.
Kernel Logs and Debugging: Review the kernel logs (dmesg) for any additional error messages or warnings related to USB. This can provide more context on the issue.
USB Hub Port Control: Consider using tools like uhubctl to manually control the power to the USB hub ports. This can help determine if the issue is related to power cycling or port control.
Driver and Firmware Updates: Make sure all relevant drivers and firmware for the USB hub and UART IC are up-to-date. Updates can often resolve compatibility issues.
Hardware Connections: Double-check all hardware connections to ensure there are no loose connections or faulty cables that might cause intermittent USB disconnections.
By following these steps, you should be able to narrow down the cause of the repeated USB messages and find a suitable solution. I hope this helps, and please feel free to reach out if you have further questions.
Best regards,
Toradex AI Assistant
Please, also check if these links can help you solve your problem:
Hi @vkj,
Since it is observed only on your custom board, it is difficult to reproduce and debug at our end.
Please send full logs from booting to where there messages are being repeated.
Also, what peripherals you have connected to USB?
Can you also test for these error in case you do not connect anything on the USB?
