Thread (11 messages) 11 messages, 3 authors, 2011-04-01
STALE5567d

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

From: Nicolas Ferre <hidden>
Date: 2011-04-01 13:33:18
Also in: lkml
Subsystem: memory technology devices (mtd), nand flash subsystem, the rest · Maintainers: Miquel Raynal, Richard Weinberger, Vignesh Raghavendra, Linus Torvalds

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 <redacted>
---
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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