mtd: cfi_cmdset_0001: Fix problem with unlocking timeout

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=7be1f6b9a1ae3476a424380b52aad7c14c3273ab
Commit:     7be1f6b9a1ae3476a424380b52aad7c14c3273ab
Parent:     a5ff4f102937a3492bca4a9ff0c341d78813414c
Author:     Stefan Roese <sr at denx.de>
AuthorDate: Tue Aug 28 11:34:13 2012 +0200
Committer:  David Woodhouse <David.Woodhouse at intel.com>
CommitDate: Sat Sep 29 15:29:08 2012 +0100

    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 at denx.de>
    Tested-by: Stephan Gatzka <stephan at gatzka.org>
    Signed-off-by: Artem Bityutskiy <artem.bityutskiy at linux.intel.com>
    Signed-off-by: David Woodhouse <David.Woodhouse at intel.com>
---
 drivers/mtd/chips/cfi_cmdset_0001.c |   14 +++++++++++---
 1 files changed, 11 insertions(+), 3 deletions(-)

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