@@ -310,7 +310,9 @@ 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++) {
@@ -360,6 +362,21 @@ 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);