mtd: cfi_cmdset_0001: Fix problem with unlocking timeout

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 <sr@denx.de>
Tested-by: Stephan Gatzka <stephan@gatzka.org>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
index dbbd2ed..7751443 100644 (file)
--- 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;