[Openvortex-dev] DMA questions

[Phil Jensen]

When allocating a DMA buffer for sample data, how big should it be?  From
what I remember of what I read, I thought that there are 4 sub-buffers, of
each which are 4k?  Does this mean I should be allocating a single chunk of
16k, or four separate chunks of 4k?

What I'm currently doing now is allocating a single 16384 byte chunk, and
setupbuffer() looks something like this: (look familiar?  :)

void vortex2_setupbuffer(struct aureal_state *softstate, unsigned long
address) {
        cmn_err(CE_NOTE, "vortex2_setupbuffer(): entered with address
0x%x\n", ad
dress);

        AUREAL_PUT32( 0x27400, address);
        AUREAL_PUT32( 0x27404, address+0x1000);
        AUREAL_PUT32( 0x27408, address+0x2000);
        AUREAL_PUT32( 0x2740c, address+0x3000);

        AUREAL_PUT32( 0x27800, 0xceffffff);
        AUREAL_PUT32( 0x27804, 0xfcffffff);
}

Phil