[MTD] make dataflash write-verify be optional

This adds a WRITE_VERIFY Kconfig option to the DataFlash driver,
closely mirroring the similar NAND and ONENAND options, giving
an option to disable some code that's currently always enabled.

Removing this step probably saves a millisecond or so per page
when writing data, which will add up quickly since these pages
are small (the largest is 1 KiB).  It doesn't seem to add a
lot in terms of reliability, and wouldn't detect errors which
crop up when transferring data to the on-chip SRAM buffer.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Acked-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 3 insertions, 5 deletions

diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c
index 90161277902b..6dd9aff8bb2d 100644
--- a/drivers/mtd/devices/mtd_dataflash.c
+++ b/drivers/mtd/devices/mtd_dataflash.c
@@ -30,12 +30,10 @@
  * doesn't (yet) use these for any kind of i/o overlap or prefetching.
  *
  * Sometimes DataFlash is packaged in MMC-format cards, although the
- * MMC stack can't use SPI (yet), or distinguish between MMC and DataFlash
+ * MMC stack can't (yet?) distinguish between MMC and DataFlash
  * protocols during enumeration.
  */
 
-#define CONFIG_DATAFLASH_WRITE_VERIFY
-
 /* reads can bypass the buffers */
 #define OP_READ_CONTINUOUS      0xE8
 #define OP_READ_PAGE            0xD2
@@ -403,7 +401,7 @@ static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len,
                 (void) dataflash_waitready(priv->spi);
 
 
-#ifdef  CONFIG_DATAFLASH_WRITE_VERIFY
+#ifdef CONFIG_MTD_DATAFLASH_VERIFY_WRITE
 
                 /* (3) Compare to Buffer1 */
                 addr = pageaddr << priv->page_offset;
@@ -432,7 +430,7 @@ static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len,
                 } else
                         status = 0;
 
-#endif  /* CONFIG_DATAFLASH_WRITE_VERIFY */
+#endif  /* CONFIG_MTD_DATAFLASH_VERIFY_WRITE */
 
                 remaining = remaining - writelen;
                 pageaddr++;