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AM3359: Can't write to DebugSS

Mat Bennion
Intellectual 410 points
Part Number: AM3359


Hi,

I can't write to the DebugSS register for EMAC suspend control, address 0x4B16_0220.  I read it as 1, write 9 to it as per the TRM, but read back 1 again (I'm guessing this is why suspend doesn't seem to be working).

After reading some other threads, I've checked the L4FW clock is enabled (0x44E0_0008 reads 0x102 and 0x44e0_0064 reads 0x2).

Is there something else I need to enable to be able to write to DebugSS registers?

  • 0
    TI__Guru**** 161600 points
    Hi Mat,

    This should be enough, however, it is possible that some memory regions are locked for user space accesses.
    In this case, if you wish to change the EMAC hardware mode (enable suspend) you can modify the ethernet related structures in arch/arm/mach-omap2/omap_hwmod_33xx_43xx_ipblock_data.c.

    Best Regards,
    Yordan
  • 0 in reply to Yordan Kovachev
    Intellectual 410 points
    Hi, please can you explain your response a bit more?

    - I can't find any reference to EMAC hardware mode in the TRM (note that I can set the Emulation Control registers within the CPSW without any problem). Most of the debug registers seem to be undocumented and marked as "reserved" in the TRM, though I can see some clues in AM335x_trace_dapdebugss.gel.

    - I don't recognise the C file you mention (is it related to OMAP rather than AM3359?).

    - I need a register-level solution as I'm not using any TI code.

    Thanks,
    Mat
  • 0 in reply to Yordan Kovachev
    Intellectual 410 points
    See subsequent post. I don't have the C file in question and I can't find reference to the EMAC hardware mode in the TRM.