Hi Hans, On Fri, Sep 12, 2014 at 8:59 PM, Hans Verkuil <hverkuil@xxxxxxxxx> wrote: > From: Hans Verkuil <hans.verkuil@xxxxxxxxx> > > This flag helps drivers that need to reprogram their DMA engine whenever > a plane cookie (== DMA address or DMA scatter-gather list) changes. > > Otherwise they would have to reprogram the DMA engine for every frame. > > Note that it is not possible to do this in buf_init() since dma_map_sg has > to be done first, which happens just before buf_prepare() in the prepare() > memop. It is dma_map_sg that sets up the dma addresses that are needed to > configure the DMA engine. Perhaps I'm missing something, but couldn't we just dma_map_sg on allocation/get in dma-sg and unmap on put? -- Best regards, Pawel Osciak -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
