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Hi All! I am trying to allocate a 5-page-800x600 frame buffer(roughly 5mb). But during DRAM memory map initialization, dma_alloc_coherent() only returns a zero pointer or does not allocate the buffer. ...
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  1. #1
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    Question dma_alloc_coherent() memory allocation failure with more than 4mb


    Hi All!

    I am trying to allocate a 5-page-800x600 frame buffer(roughly 5mb). But during DRAM memory map initialization, dma_alloc_coherent() only returns a zero pointer or does not allocate the buffer. It used to work with just allocating a 4-page frame buffer(4mb).
    I have already tried setting CONSISTENT_DMA_SIZE to 8mb, 10mb, and 12mb. But this doesn't seem to have any effect. Is there any other setting I'm over looking?

    BTW, my Kernel Version is 2.6.10. I wonder of this version cannot support large memory allocations.

    thanks alot,

    nazekimi
    Last edited by nazekimi; 12-09-2011 at 06:47 AM. Reason: added information

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