diff options
Diffstat (limited to 'drivers/mtd/nand/davinci_nand.c')
| -rw-r--r-- | drivers/mtd/nand/davinci_nand.c | 17 | 
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/mtd/nand/davinci_nand.c b/drivers/mtd/nand/davinci_nand.c index 9c9d893affe..2ac7367afe7 100644 --- a/drivers/mtd/nand/davinci_nand.c +++ b/drivers/mtd/nand/davinci_nand.c @@ -311,7 +311,9 @@ static int nand_davinci_correct_4bit(struct mtd_info *mtd,  	unsigned short ecc10[8];  	unsigned short *ecc16;  	u32 syndrome[4]; +	u32 ecc_state;  	unsigned num_errors, corrected; +	unsigned long timeo = jiffies + msecs_to_jiffies(100);  	/* All bytes 0xff?  It's an erased page; ignore its ECC. */  	for (i = 0; i < 10; i++) { @@ -361,6 +363,21 @@ compare:  	 */  	davinci_nand_writel(info, NANDFCR_OFFSET,  			davinci_nand_readl(info, NANDFCR_OFFSET) | BIT(13)); + +	/* +	 * ECC_STATE field reads 0x3 (Error correction complete) immediately +	 * after setting the 4BITECC_ADD_CALC_START bit. So if you immediately +	 * begin trying to poll for the state, you may fall right out of your +	 * loop without any of the correction calculations having taken place. +	 * The recommendation from the hardware team is to wait till ECC_STATE +	 * reads less than 4, which means ECC HW has entered correction state. +	 */ +	do { +		ecc_state = (davinci_nand_readl(info, +				NANDFSR_OFFSET) >> 8) & 0x0f; +		cpu_relax(); +	} while ((ecc_state < 4) && time_before(jiffies, timeo)); +  	for (;;) {  		u32	fsr = davinci_nand_readl(info, NANDFSR_OFFSET);  |