On 13 April 2018 at 11:39, Vinod Koul <vinod.koul@xxxxxxxxx> wrote: > On Thu, Apr 12, 2018 at 07:30:01PM +0800, Baolin Wang wrote: > >> >> > what does block and transaction len refer to here >> >> >> >> Our DMA has 3 transfer mode: transaction transfer, block transfer and >> >> fragment transfer. One transaction transfer can contain several blocks >> >> transfer, and each block can be set proper block step. One block can >> >> contain several fragments transfer with proper fragment step. It can >> >> generate interrupts when one transaction transfer or block transfer or >> >> fragment transfer is completed if user set the interrupt type. So here >> >> we should set the length for transaction transfer, block transfer and >> >> fragment transfer. >> > >> > what are the max size these types support? >> >> These types max size definition: >> >> #define SPRD_DMA_FRG_LEN_MASK GENMASK(16, 0) >> >> #define SPRD_DMA_BLK_LEN_MASK GENMASK(16, 0) >> >> #define SPRD_DMA_TRSC_LEN_MASK GENMASK(27, 0) > > They are register defines. How many items or bytes do each type of txn > support? These macros are the max size definitions, for example one fragment length can support to 0x1ffff bytes, one transaction transfer can support to 0xfffffff. -- Baolin.wang Best Regards -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
