Hi,

      

        

          

            

              

                

                  
I am debugging the DMA bug now. and I will send it out when i fix it.



                

                
What sort of DMA bug?



              

              
The DMA may time-out. :(

The DMA time-out may occur in two situations:
[1] send a command DMA descriptor, see the nfc->send_command() function.
[2] read the non-ecc data from nand, see the nfc->read_data() function.

I don't know why. Maybe caused by the timing, or something else.


            

          

          
I am confused. The send-command DMA timeout prevents any write for me.
You guys surely would have noticed if you have been bitten as well. Does
it depend on the NAND chip?


        

        
I think It does not depend on the NAND chip.
My test chip is Samsung K9G8G08U0M.
Sometimes, I can run a long time while there is no DMA timeout occurring;
Sometimes, the bug appears right away.


      

      
For me, the bug always happens right away. So, if you need logs or debug
output or can give me a pointer into some direction, I am glad to
assist.



    

    Thanks a lot. :)

    

    I am trying to merge the two DMA descriptors into one in the
    send_command().

    The original bsp code used only one DMA descriptor.

    

    

    

    Huang Shijie

    

      

      

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