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EVMK2H: EVMK2H don't support USB hub

JackyXiaodong
Intellectual 945 points

Part Number: EVMK2H

Hi,

Recently, I use USB 3.0 hub connect to EVMK2H,so I could use more USB devices.

But I find out that when my USB device connect to USB  hub , Linux will keep printing error message on Terminal

When I connect to EVMK2H directly without USB hub, it's OK .

And I switch other USB 2.0  hub, it still have this issue and keep printing error message.

I use mcsdk_linux_3_01_04_07 on my EVMK2H.

I this Linux is old version.

I want to know is there anything wrong on  my hardware?

Or EVMK2H don't support USB hub?

Any information will be appreciative. Thanks very much.

Jacky

  • 0
    TI__Guru**** 161600 points

    Hi Jacky,

    The source of the above error code is drivers/usb/core/hub.c:
            retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
        if (retval < (signed)sizeof(udev->descriptor)) {
            if (retval != -ENODEV)
                dev_err(&udev->dev, "device descriptor read/all, error %d\n",
                        retval);
            if (retval >= 0)
                retval = -ENOMSG;
            goto fail;

    You can trace the error nomer to include/uapi/asm-generic/errno-base.h:
      #define    ECHILD        10    /* No child processes */ .

    Unfortunately there is no more explanation about this error in the kernel. Since this happens with other usb hubs as well, I can suggest to try with the latest Processor SDK Linux to see if this has been fixed. The board should be able to work with usb hubs.

    Best Regards,

    Yordan

  • 0 in reply to Yordan Kovachev
    Intellectual 945 points

    Hi,Yordan

    Thanks for your information.

    I found out that my USB device , USB hub and EVMK2H have the timing sequence problem.

    After I finish starting up the EVMK2H , and then  power up my USB device. The error message don't happen and work normally.

    And I found out that when EVMK2H start up ,USB power don't output.

    So I change my devices start sequence ,now it is OK.

    Thanks.

    Best Regards

    Jacky