[U-Boot] [PATCH V2 3/3] mtd: nand: mxs invalidate dcache before DMA read

Peng Fan
2015-07-21T08:15:21Z

Follow linux dma flow:
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>
Acked-by: Marek Vasut <marex@denx.de>
---

Changes v2:
Add Marek's Acked by

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