memory map problem for edma

Danillo Graziosi

Dear all,

In my application I use mmap to map the frame buffer memory to user space memory

fdHandle = open ("/dev/fb0", O_RDWR);

memADDR = mmap (0, nBufferSize * IL_CLIENT_FB_INPUT_BUFFER_COUNT, (PROT_READ | PROT_WRITE), MAP_SHARED, (int32_t)fbHandle, 0))

And I am able to successfully copy to this memory using memcpy. Now I am using edma for my memory copy operations, and I try to get the physical address with the following function:

Memory_translate(memADDR, Memory_XltFlags_Virt2Phys)

But the return of this function is 0. Is there any way I can obtain the physical address of the frame buffer memory, to enable the edma to copy from one memory position to the frame buffer?

Thanks,

Danillo

over 10 years ago

0 Margarita Gashova over 10 years ago

TI__Guru* 80190 points

Hello,

You could check here:

http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/716/p/335337/1171030.aspx

Best Regards,

Margarita

0 Danillo Graziosi over 10 years ago in reply to Margarita Gashova

Intellectual 480 points

Hi Margarita,

I was able to obtain the physical address of the FB by using the ioctl call ioctl (display_fd, FBIOGET_FSCREENINFO, fixinfo); and using the physical address printf ("Physical Address = %lx\n", fixinfo->smem_start);

However, I am still having problems with the edma driver. I based my driver on the example cited by you (edma_test), but in this example, the buffers are allocated by the kernel module using dma_alloc_coherent(). In my module, I pass the physical addresses using

module_param(dstBuf, int, S_IRUGO);
module_param(srcBuf, int, S_IRUGO);
module_param(bufSize, int, S_IRUGO);

I see that the module is receiving the correct address, however the copy is not done. I basically call the function result = edma3_memtomemcpytest_dma(bufSize, 1, 1, 1 1); to perform the copy (with the appropriate adaptations to use the input buffers).

Is there any address translation that I need to do inside the module? Do you have any suggestions?

Thanks,

Danillo

0 Danillo Graziosi over 10 years ago in reply to Danillo Graziosi

Intellectual 480 points

Hi Margarita,

do you have any suggestions on this problem that I am facing? Is there any specific address translation that needs to be done for the EDMA?

Thanks,

Danillo

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memory map problem for edma