From patchwork Thu May 14 08:28:42 2009
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Subject: oobavail size calculation error in nand_base.c
Date: Wed, 13 May 2009 22:28:42 -0000
From: Jinyoung Park <parkjy@mtekvision.com>
X-Patchwork-Id: 27202
Message-Id: <280b69ac0905140128u135f8b2aua50114faebb593e0@mail.gmail.com>
To: tglx@linutronix.de
Cc: linux-mtd@lists.infradead.org

Hello.

I found error in nand_base.c.
In nand_scan_tail() function, oobavail size calculation result is
wrong as follow circumstances.
    - Define nand_ecclayout using full oobfree array like below.
	.oobfree = { {2, 6}, {11, 2}, {16, 8}, {27, 2}, {32, 8}, {43, 2},{48,
8}, {59, 2} }
    - Using ARM EABI cross compiler when kernel compile also enable
"Use the ARM EABI to compile the kernl" feature in kernel menuconfig.
      I using ARM EABI compiler that codesourcery release arm-2008q3-51.

In this case, right oobavail size is 38 but result is too much
value(e.g. 2703572308...). It's random.
I think sometimes happen that after beyond oobfree array(oobfree[8])
is not 0 when ARM EABI compilation.
Below codes are my modified code. Please check...

Thanks.

Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/


diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 3d7ed43..abb5998 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2756,9 +2756,12 @@ int nand_scan_tail(struct mtd_info *mtd)
	* the out of band area
	*/
	chip->ecc.layout->oobavail = 0;
-	for (i = 0; chip->ecc.layout->oobfree[i].length; i++)
+	for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
+	if (chip->ecc.layout->oobfree[i].length == 0)
+		break;
	chip->ecc.layout->oobavail +=
		chip->ecc.layout->oobfree[i].length;
+	}
	mtd->oobavail = chip->ecc.layout->oobavail;

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