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

Clemens Ladisch clemens at ladisch.de
Thu Feb 14 18:46:30 CET 2013

Adrian Knoth 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.  But then you don't need SG in the first place.

> Better use SNDRV_DMA_TYPE_DEV instead?



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