[U-Boot] [PATCH] nand/davinci: make sure ECC calculation has really started
Wolfram Sang
w.sang at pengutronix.de
Thu Sep 9 13:54:41 CEST 2010
Due to a register glitch (result code <4 might show up right after the
start-calculation-bit was set), make sure the ECC has really started.
See 1c3275b656045aff9a75bb2c9f3251af1043ebb3 in the kernel.
Signed-off-by: Wolfram Sang <w.sang at pengutronix.de>
Cc: Sandeep Paulraj <s-paulraj at ti.com>
---
drivers/mtd/nand/davinci_nand.c | 15 ++++++++++++++-
1 files changed, 14 insertions(+), 1 deletions(-)
diff --git a/drivers/mtd/nand/davinci_nand.c b/drivers/mtd/nand/davinci_nand.c
index 4ca738e..c5a86d6 100644
--- a/drivers/mtd/nand/davinci_nand.c
+++ b/drivers/mtd/nand/davinci_nand.c
@@ -484,7 +484,20 @@ static int nand_davinci_4bit_correct_data(struct mtd_info *mtd, uint8_t *dat,
__raw_writel(1 << 13, &davinci_emif_regs->nandfcr);
/*
- * Wait for the corr_state field (bits 8 to 11)in the
+ * Wait for the corr_state field (bits 8 to 11) in the
+ * NAND Flash Status register to be not equal to 0x0, 0x1, 0x2, or 0x3.
+ * Otherwise ECC calculation has not even begun and the next loop might
+ * fail because of a false positive!
+ */
+ i = NAND_TIMEOUT;
+ do {
+ val = __raw_readl(&davinci_emif_regs->nandfsr);
+ val &= 0xc00;
+ i--;
+ } while ((i > 0) && !val);
+
+ /*
+ * Wait for the corr_state field (bits 8 to 11) in the
* NAND Flash Status register to be equal to 0x0, 0x1, 0x2, or 0x3.
*/
i = NAND_TIMEOUT;
--
1.7.1
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