Follow linux dma follow: Before DMA read, be sure to invalidate the cache over the address range of DMA buffer to prevent cache coherency problems. After DMA read, invalidate dcache again.
Signed-off-by: Peng Fan Peng.Fan@freescale.com --- drivers/mtd/nand/mxs_nand.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/mtd/nand/mxs_nand.c b/drivers/mtd/nand/mxs_nand.c index 97011b2..f15cf36 100644 --- a/drivers/mtd/nand/mxs_nand.c +++ b/drivers/mtd/nand/mxs_nand.c @@ -469,6 +469,9 @@ static void mxs_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int length)
mxs_dma_desc_append(channel, d);
+ /* Invalidate caches */ + mxs_nand_inval_data_buf(nand_info); + /* Execute the DMA chain. */ ret = mxs_dma_go(channel); if (ret) { @@ -635,6 +638,9 @@ static int mxs_nand_ecc_read_page(struct mtd_info *mtd, struct nand_chip *nand,
mxs_dma_desc_append(channel, d);
+ /* Invalidate caches */ + mxs_nand_inval_data_buf(nand_info); + /* Execute the DMA chain. */ ret = mxs_dma_go(channel); if (ret) {