[PATCH 1/3 v2] MTD: atmel_nand: modify test case for using DMA operations

From: Nicolas Ferre
Date: Fri Apr 01 2011 - 09:33:20 EST


We have better performances not using DMA for oob operations.
Modify size test so that it is using DMA for size greater than oobsize.

Signed-off-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
---
Artem,

Here is the v2 version with embedded comment as you suggested.

Best regards,

drivers/mtd/nand/atmel_nand.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index 6fae04b..5872f2a 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -280,7 +280,8 @@ static void atmel_read_buf(struct mtd_info *mtd, u8 *buf, int len)
struct nand_chip *chip = mtd->priv;
struct atmel_nand_host *host = chip->priv;

- if (use_dma && len >= mtd->oobsize)
+ if (use_dma && len > mtd->oobsize)
+ /* only use DMA for bigger than oob size: better performances */
if (atmel_nand_dma_op(mtd, buf, len, 1) == 0)
return;

@@ -295,7 +296,8 @@ static void atmel_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
struct nand_chip *chip = mtd->priv;
struct atmel_nand_host *host = chip->priv;

- if (use_dma && len >= mtd->oobsize)
+ if (use_dma && len > mtd->oobsize)
+ /* only use DMA for bigger than oob size: better performances */
if (atmel_nand_dma_op(mtd, (void *)buf, len, 0) == 0)
return;

--
1.7.3

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