mtd: cfi_cmdset_0001: Fix problem with unlocking timeout

stroese · David Woodhouse · commit 7be1f6b9a1ae · 2012-09-29T15:29:08.000+01:00
Unlocking may take up to 1.4 seconds on some Intel flashes. So
lets use a max. of 1.5 seconds (1500ms) as timeout.

See "Clear Block Lock-Bits Time" on page 40 in
"3 Volt Intel StrataFlash Memory" 28F128J3,28F640J3,28F320J3 manual
from February 2003

This patch also fixes some other problems with this timeout:

- Don't use HZ in timeout "calculation"!
  While testing we noticed that an unlocking timeout occured with
  HZ=1000 and didn't occur with HZ=300. This was because the
  timeout parameter was calculated differently depending on the
  HZ value. Now a fixed value of 1500ms is used.

- The last parameter of WAIT_TIMEOUT (defined to
  inval_cache_and_wait_for_operation) has to be passed in
  micro-seconds. So multiply the ms value with 1000 and not 100
  to calculate this value.

- Use variable name "mdelay" instead of misleading "udelay".

Signed-off-by: Stefan Roese &lt;sr@denx.de&gt;
Tested-by: Stephan Gatzka &lt;stephan@gatzka.org&gt;
Signed-off-by: Artem Bityutskiy &lt;artem.bityutskiy@linux.intel.com&gt;
Signed-off-by: David Woodhouse &lt;David.Woodhouse@intel.com&gt;
diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
@@ -2043,7 +2043,7 @@ static int __xipram do_xxlock_oneblock(struct map_info *map, struct flchip *chip
 {
 	struct cfi_private *cfi = map->fldrv_priv;
 	struct cfi_pri_intelext *extp = cfi->cmdset_priv;
-	int udelay;
+	int mdelay;
 	int ret;
 
 	adr += chip->start;
@@ -2072,9 +2072,17 @@ static int __xipram do_xxlock_oneblock(struct map_info *map, struct flchip *chip
 	 * If Instant Individual Block Locking supported then no need
 	 * to delay.
 	 */
-	udelay = (!extp || !(extp->FeatureSupport & (1 << 5))) ? 1000000/HZ : 0;
+	/*
+	 * Unlocking may take up to 1.4 seconds on some Intel flashes. So
+	 * lets use a max of 1.5 seconds (1500ms) as timeout.
+	 *
+	 * See "Clear Block Lock-Bits Time" on page 40 in
+	 * "3 Volt Intel StrataFlash Memory" 28F128J3,28F640J3,28F320J3 manual
+	 * from February 2003
+	 */
+	mdelay = (!extp || !(extp->FeatureSupport & (1 << 5))) ? 1500 : 0;
 
-	ret = WAIT_TIMEOUT(map, chip, adr, udelay, udelay * 100);
+	ret = WAIT_TIMEOUT(map, chip, adr, mdelay, mdelay * 1000);
 	if (ret) {
 		map_write(map, CMD(0x70), adr);
 		chip->state = FL_STATUS;
