[MTD] [NAND] OMAP2: add retry after read timeout

Very occasionally, (about one in a million) read operations are
ongoing after the timeout has expired.  So, retry three times
while the ongoing bit remains set.

Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This commit is contained in:
Adrian Hunter 2008-08-25 12:01:31 +03:00 committed by David Woodhouse
parent 34f6e15786
commit 8afbc11454

View file

@ -187,16 +187,36 @@ static int omap2_onenand_wait(struct mtd_info *mtd, int state)
}
}
} else {
int retry_cnt = 0;
/* Turn interrupts off */
syscfg = read_reg(c, ONENAND_REG_SYS_CFG1);
syscfg &= ~ONENAND_SYS_CFG1_IOBE;
write_reg(c, syscfg, ONENAND_REG_SYS_CFG1);
timeout = jiffies + msecs_to_jiffies(20);
while (time_before(jiffies, timeout)) {
intr = read_reg(c, ONENAND_REG_INTERRUPT);
if (intr & ONENAND_INT_MASTER)
while (1) {
if (time_before(jiffies, timeout)) {
intr = read_reg(c, ONENAND_REG_INTERRUPT);
if (intr & ONENAND_INT_MASTER)
break;
} else {
/* Timeout after 20ms */
ctrl = read_reg(c, ONENAND_REG_CTRL_STATUS);
if (ctrl & ONENAND_CTRL_ONGO) {
/*
* The operation seems to be still going
* so give it some more time.
*/
retry_cnt += 1;
if (retry_cnt < 3) {
timeout = jiffies +
msecs_to_jiffies(20);
continue;
}
}
break;
}
}
}