[U-Boot] [PATCH 3/3] mtd: nand: mxs invalidate dcache before DMA read

[Peng Fan]

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 at 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) {
-- 
1.8.4