From 584db6a1b5b80513b272b788e5bda43da982817a Mon Sep 17 00:00:00 2001 From: Samu Onkalo Date: Fri, 3 Sep 2010 19:20:19 +0800 Subject: crypto: omap-sham - Adjust DMA parameters DMA is set to use burst mode also for source channel. It should descrease memory bandwidth needs. DMA synchronization is set to use prefetch mechanism. SHAM block is behind L4 bus and it doesn't have fifo. SHAM block is stalling as long as the new data is available. It takes time to fetch data from memory and transfer it via L4 bus. With prefetch enabled, data is waiting in DMA fifo and SHAM block receives new data block faster. This increases SHA processing speed up to 30 percent depending on the bus / memory load. Signed-off-by: Samu Onkalo Signed-off-by: Dmitry Kasatkin Signed-off-by: Herbert Xu --- drivers/crypto/omap-sham.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/crypto') diff --git a/drivers/crypto/omap-sham.c b/drivers/crypto/omap-sham.c index 7d1485676886..a081c7c7d03f 100644 --- a/drivers/crypto/omap-sham.c +++ b/drivers/crypto/omap-sham.c @@ -311,7 +311,8 @@ static int omap_sham_xmit_dma(struct omap_sham_dev *dd, dma_addr_t dma_addr, len32 = DIV_ROUND_UP(length, sizeof(u32)); omap_set_dma_transfer_params(dd->dma_lch, OMAP_DMA_DATA_TYPE_S32, len32, - 1, OMAP_DMA_SYNC_PACKET, dd->dma, OMAP_DMA_DST_SYNC); + 1, OMAP_DMA_SYNC_PACKET, dd->dma, + OMAP_DMA_DST_SYNC_PREFETCH); omap_set_dma_src_params(dd->dma_lch, 0, OMAP_DMA_AMODE_POST_INC, dma_addr, 0, 0); @@ -1072,6 +1073,9 @@ static int omap_sham_dma_init(struct omap_sham_dev *dd) omap_set_dma_dest_burst_mode(dd->dma_lch, OMAP_DMA_DATA_BURST_16); + omap_set_dma_src_burst_mode(dd->dma_lch, + OMAP_DMA_DATA_BURST_4); + return 0; } -- cgit v1.2.3-59-g8ed1b