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DMA Driver problem

Former Member

Hi,
I am writing a driver for my application which use a DMA and XADC IP in PL and I have some problem.

I connected the Stream port of XADC IP on AXIS_S2MM port of DMA and I writed a driver.

When the driver is waiting for the transfert to complete :
timeout = wait_for_completion_timeout(&rx_cmp, timeout);
I have a time out (timeout = 0).

I tried with a loopback on AXIS_S2MM and AXIS_MM2S but I have the problem.

I compared my driver with an other that I found on Xilinx Forum ant they look like same.

Have you any why I have this problem ?

Thanks
Jo

  • 0

    Hi,



    I writed a simple program in order to read DMA register with /dev/mem :


    #include <stdio.h>
    #include <unistd.h>
    #include <stdlib.h>
    #include <fcntl.h>
    #include <string.h>
    #include <sys/mman.h>

    #define         DMA_BASEADDR            0xB0000000

    #define         MM2S_DMACR              0x0
    #define         MM2S_DMASR              0x4
    #define         MM2S_SA                 0X18
    #define         MM2S_LENGTH             0x28

    #define         S2MM_DMACR              0x30
    #define         S2MM_DMASR              0x34
    #define         S2MM_DA                 0X48
    #define         S2MM_LENGTH             0x58

    int main()
    {
            int fd = 0, page_size = 0;
            unsigned int *dma_addr = NULL;

            if((fd = open("/dev/mem",O_RDWR)) < 1)
            {
                    printf("Open failed
    ");
                    return 0;
            }

            page_size = sysconf(_SC_PAGESIZE);

            dma_addr = (unsigned int*)mmap(NULL, page_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, DMA_BASEADDR);
            if(dma_addr == NULL)
            {
                    printf("dma_addr failed
    ");
                    close(fd);
                    return 0;
            }

            unsigned int reg = *(dma_addr + MM2S_DMACR / sizeof(unsigned int));
            printf("MM2S_DMACR 0x%08x
    ",reg);
            reg = *(dma_addr + MM2S_DMASR / sizeof(unsigned int));
            printf("MM2S_DMASR 0x%08x
    ",reg);
            reg = *(dma_addr + MM2S_SA / sizeof(unsigned int));
            printf("MM2S_SA 0x%08x
    ",reg);
            reg = *(dma_addr + MM2S_LENGTH / sizeof(unsigned int));
            printf("MM2S_LENGTH 0x%08x
    ",reg);
            reg = *(dma_addr + S2MM_DMACR / sizeof(unsigned int));
            printf("S2MM_DMACR 0x%08x
    ",reg);
            reg = *(dma_addr + S2MM_DMASR / sizeof(unsigned int));
            printf("S2MM_DMASR 0x%08x
    ",reg);
            reg = *(dma_addr + S2MM_DA / sizeof(unsigned int));
            printf("S2MM_DA 0x%08x
    ",reg);
            reg = *(dma_addr + S2MM_LENGTH / sizeof(unsigned int));
            printf("S2MM_LENGTH 0x%08x
    ",reg / sizeof(unsigned int));

            close(fd);
            return 0;
    }



    And I have an unexpected result after starting the driver :

    S2MM_DMACR : 0x17003

    S2MM_DMASR : 0x0

    S2MM_DA : 0x0

    S2MM_LENGTH : 0x0



    MM2S_DMACR : 0x17003

    MM2S_DMASR : 0x0

    MM2S_SA : 0x0

    MM2S_LENGTH : 0x0



    I really lost, I don't what's going wrong the returns values of statues are set to zero.



    Jo

  • 0

    Hi,



    Is it possible to have one VDMA and one DMA at the same time in the PL and use xilinx_vdma.c module for the VDMA and xilinx_axidma.c for the DMA ?



    Thanks

    Jo

  • 0

    And if I use DMA controller in PS and I add a DMA IP in PL, is it going to work ?

    Jo