[SOLVED] J-Link stops working after Linux starts

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  • [SOLVED] J-Link stops working after Linux starts

    HI,

    I have SAM ICE connected to AT91SAM9x25.
    I am using J-Link commander (on Windows) to connect to it. The problem i have is that the commander work while the board is in uboot. As soon as Linux boots, connection gets lost.


    I can see same discussion in this thread.
    http://forum.segger.com/index.php?page=Thread&threadID=1104



    Answer to your question on that thread.
    What happens if you start J-Link Commander AFTER Linux is already booted?: NO connection.gives error
    Is it still able to detect the device properly?: NO connection.gives error




    can you please explain more.

    Br,
    Vinayak
  • Hi,

    which J-Link software version are you using currently?
    Is Linux booting with some start parameters that would terminate connections to the debugger?
    We have no control over what Linux does to the target device. So make sure the JTAG pins stay mapped as they were.

    Best regards,
    Nino
    Please read the forum rules before posting.

    Keep in mind, this is *not* a support forum.
    Our engineers will try to answer your questions between their projects if possible but this can be delayed by longer periods of time.
    Should you be entitled to support you can contact us via our support system: segger.com/ticket/

    Or you can contact us via e-mail.
  • Hello,

    I don't know if there are any such start parameters.


    We cannot know that either. This is a Linux related issue, not J-Link.
    I suggest seeking out a Linux forum of the OS you are using.

    Best regards,
    Nino
    Please read the forum rules before posting.

    Keep in mind, this is *not* a support forum.
    Our engineers will try to answer your questions between their projects if possible but this can be delayed by longer periods of time.
    Should you be entitled to support you can contact us via our support system: segger.com/ticket/

    Or you can contact us via e-mail.
  • Probably linux is gating off whatever clock is running the JTAG port.

    Try configuring your linux kernel with CONFIG_CPU_IDLE disabled.

    If it's not that, then probably something else is interfering with the JTAG peripheral on the SAM. Check whether the pinmux is remapping whatever pins are being used for the JTAG.

    The post was edited 1 time, last by jpetri ().