From: Hector Palacios <hector.palacios@digi.com>
Date: Mon, 18 Jul 2016 07:37:41 +0000 (+0200)
Subject: mtd: nand: fix bug writing 1 byte less than page size
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=ebb7febc92fc628d1f37b96616a1bb21b646d072;p=project%2Fbcm63xx%2Fu-boot.git

mtd: nand: fix bug writing 1 byte less than page size

nand_do_write_ops() determines if it is writing a partial page with the
formula:
	part_pagewr = (column || writelen < (mtd->writesize - 1))

When 'writelen' is exactly 1 byte less than the NAND page size the formula
equates to zero, so the code doesn't process it as a partial write, although
it should.
As a consequence the function remains in the while(1) loop with 'writelen'
becoming 0xffffffff and iterating until the watchdog timeout triggers.

To reproduce the issue on a NAND with 2K page (0x800):
	=> nand erase.part <partition>
	=> nand write $loadaddr <partition> 7ff

Signed-off-by: Hector Palacios <hector.palacios@digi.com>
---

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 4cf4518989..d1287bc3be 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2414,7 +2414,7 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
 		int cached = writelen > bytes && page != blockmask;
 		uint8_t *wbuf = buf;
 		int use_bufpoi;
-		int part_pagewr = (column || writelen < (mtd->writesize - 1));
+		int part_pagewr = (column || writelen < mtd->writesize);
 
 		if (part_pagewr)
 			use_bufpoi = 1;