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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Paul Cercueil <paul@crapouillou.net>,
        Miquel Raynal <miquel.raynal@bootlin.com>
Subject: [PATCH 5.16 0019/1039] mtd: rawnand: davinci: Avoid duplicated page read
Date:   Mon, 24 Jan 2022 19:30:08 +0100
Message-Id: <20220124184125.786487110@linuxfoundation.org>
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From: Paul Cercueil <paul@crapouillou.net>

commit 9c9d709965385de5a99f84b14bd5860e1541729e upstream.

The function nand_davinci_read_page_hwecc_oob_first() first reads the
OOB data, extracts the ECC information, programs the ECC hardware before
reading the actual data in a loop.

Right after the OOB data was read, it called nand_read_page_op() to
reset the read cursor to the beginning of the page. This caused the
first page to be read twice: in that call, and later in the loop.

Address that issue by changing the call to nand_read_page_op() to
nand_change_read_column_op(), which will only reset the read cursor.

Cc: <stable@vger.kernel.org> # v5.2
Fixes: a0ac778eb82c ("mtd: rawnand: ingenic: Add support for the JZ4740")
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20211016132228.40254-2-paul@crapouillou.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/mtd/nand/raw/davinci_nand.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/mtd/nand/raw/davinci_nand.c
+++ b/drivers/mtd/nand/raw/davinci_nand.c
@@ -401,7 +401,8 @@ static int nand_davinci_read_page_hwecc_
 	if (ret)
 		return ret;
 
-	ret = nand_read_page_op(chip, page, 0, NULL, 0);
+	/* Move read cursor to start of page */
+	ret = nand_change_read_column_op(chip, 0, NULL, 0, false);
 	if (ret)
 		return ret;