22 Jun
2015
22 Jun
'15
8:43 a.m.
On 06/22/2015 04:35 AM, Raymond Yau wrote:
DMA_RESIDUE_GRANULARITY_BURST means it can report the position with a
granularity of a few samples. Typically half the audio FIFO size.
How many soc driver/platform dma engine support DMA_RESIDUE_GRANULARITY_BURST ?
Not sure, maybe half of them. But most of the time it is a software restriction rather than a hardware restriction and more and more drivers are supporting it.
Are all soc audio driver use cyclic dma ?
I'm not sure I understand the question. All audio drivers use some kind of cyclic DMA. ASoC platforms which do not have a dedicated audio DMA typically use dmaengine for this, while others which have dedicated audio DMA do the DMA as part of the audio driver.