Re: [alsa-devel] Allocating DMA buffer for non-PCM

On Thu, Feb 14, 2013 at 06:46:30PM +0100, Clemens Ladisch wrote:

...

Would you say that the following is the proper way to allocate a DMA buffer used to hold level data?

err = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV_SG, snd_dma_pci_data(hdspm->pci), MADIFX_LEVEL_BUFFER_SIZE, &hdspm->dmaLevelBuffer);

hdspm->level_buffer = snd_sgbuf_get_ptr(&(hdspm->dmaLevelBuffer), 0);

I don't see the code asking for the address of the second page, so I guess there isn't one.

Exactly.

Just to be sure: Takashi has recommended to use (u32*)dmaLevelBuffer.area. Even in the case of SG buffers, is this virtual address continuous and safe for memset?

Cheers