From: Samu Onkalo <samu.p.onkalo@xxxxxxxxx> 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 <samu.p.onkalo@xxxxxxxxx> Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@xxxxxxxxx> --- drivers/crypto/omap-sham.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-) diff --git a/drivers/crypto/omap-sham.c b/drivers/crypto/omap-sham.c index 7d14856..a081c7c 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; } -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
