[MTD] [NAND] fix race in nand_base.c

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=c0b8ba7bfe7b4c1f11b3356b65520405b005bd33
Commit:     c0b8ba7bfe7b4c1f11b3356b65520405b005bd33
Parent:     0bf9733d0d65ebb413d62204ad8e328e0a0b9407
Author:     Artem Bityutskiy <Artem.Bityutskiy at nokia.com>
AuthorDate: Mon Jul 23 16:06:50 2007 +0300
Committer:  David Woodhouse <dwmw2 at infradead.org>
CommitDate: Mon Jul 23 13:09:52 2007 +0100

    [MTD] [NAND] fix race in nand_base.c
    
    When we mark block bad we have to get chip because this involves
    writing to the page's OOB. We hit this bug in UBI - we observed
    random obscure crashes when it marks block bad from the background
    thread and there is some parallel task which utilizes flash.
    
    This patch also adds a TODO note about BBT table protection which
    it seems does not exist.
    
    Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy at nokia.com>
    Signed-off-by: David Woodhouse <dwmw2 at infradead.org>
---
 drivers/mtd/nand/nand_base.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 25673ea..24ac677 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -24,6 +24,7 @@
  *	if we have HW ecc support.
  *	The AG-AND chips have nice features for speed improvement,
  *	which are not supported yet. Read / program 4 pages in one go.
+ *	BBT table is not serialized, has to be fixed
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -360,6 +361,7 @@ static int nand_default_block_markbad(struct mtd_info *mtd, loff_t ofs)
 		/* We write two bytes, so we dont have to mess with 16 bit
 		 * access
 		 */
+		nand_get_device(chip, mtd, FL_WRITING);
 		ofs += mtd->oobsize;
 		chip->ops.len = chip->ops.ooblen = 2;
 		chip->ops.datbuf = NULL;
@@ -367,9 +369,11 @@ static int nand_default_block_markbad(struct mtd_info *mtd, loff_t ofs)
 		chip->ops.ooboffs = chip->badblockpos & ~0x01;
 
 		ret = nand_do_write_oob(mtd, ofs, &chip->ops);
+		nand_release_device(mtd);
 	}
 	if (!ret)
 		mtd->ecc_stats.badblocks++;
+
 	return ret;
 }