JTAG cannot debug in sleep mode

[jeanguyomarch]

Hello,

I have a random bug that occurs sometimes after an i.MX28 enters in sleep mode.

I'm using TRACE32 by Lauterbach to try to monitor the evolution of the kernel code and try to determine whether Linux is stuck somewhere, get the last value of the PC, etc.

However, when the i.MX28 enters in sleep mode, TRACE32 fails to determine what code is Linux executing: there is a "task error" on the JTAG side. After wake-up, I can monitor the execution of Linux as expected.

I've read that debuggers may be disabled during sleep mode, and I would like to know what is expected behaviour of the i.MX28. I could not found a relevant information on this subject in the reference manual.

Is it even possible to debug with a JTAG probe during sleep mode?

Thank you.

Best regards,

Jean

[igorpadykov · Accepted solution]

Hi Jean

please refer to description of low power modes in attached Linux

Manual Chapter 8 i.MX28 Static Power Management Driver.

In these modes porocessor stops with WFI command execution

and seems there is no way to debug it.

Best regards

igor

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