Forum Discussion

AHart2's avatar
AHart2
Icon for New Contributor rankNew Contributor
7 years ago
Solved

Hello, is there a known problem with the ethernet MACs DMA controller in the CYCLONE V SOC devices ?

I observe the EMACS DMA controller fails to correctly update the descriptors status in DMA ring mode. What I can clearly see is that within the rx-ring single descriptors are omitted i.e. the own bi...
  • AHart2's avatar
    7 years ago

    Dear Anand,

    Dear Nooraini,

    thank you for getting back to me and sorry for my late reply.

    Meanwhile it seems that we have found the reason for the failing

    DMA transfers from GMAC. The 'shared attributes override' Bit in

    the L2C Cache controllers AUX_CONTROL Register must be set to

    one. This can be done either via bootloader patch or by adding the

    "arm,shared-override" parameter to the L2C node in the devicetree.

    Otherwise the Rx Path fails after some minutes when theres high

    network traffic.

    @ Anand : Yes I was able to ping the description. I have added some debug

    code to the driver to output the descriptor ring immediately when the DMA#

    fails.

    Please close this request.

    All the best,

    Andre