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From:   Liu Xiang <liu.xiang6@zte.com.cn>
To:     linux-mtd@lists.infradead.org
Cc:     linux-kernel@vger.kernel.org, boris.brezillon@bootlin.com,
        marek.vasut@gmail.com, dwmw2@infradead.org,
        computersforpeace@gmail.com, richard@nod.at, liuxiang_1999@126.com,
        Liu Xiang <liu.xiang6@zte.com.cn>
Subject: [PATCH] mtd: spi-nor: Return error when nor->addr_width not match the device size
Date:   Wed, 14 Nov 2018 20:56:05 +0800
Message-Id: <1542200165-3073-1-git-send-email-liu.xiang6@zte.com.cn>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

In is25lp256, the DWORD1 of JEDEC Basic Flash Parameter Header
is 0xfff920e5. So the DWORD1[18:17] Address Bytes bits are 0b00,
means that 3-Byte only addressing. But the device size is larger
than 16MB, nor->addr_width must be 4 to access the whole address.
An error should be returned when nor->addr_width not match
the device size in spi_nor_parse_sfdp().

Suggested-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Liu Xiang <liu.xiang6@zte.com.cn>
---
 drivers/mtd/spi-nor/spi-nor.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 3eba13a..77eaf22 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -2669,6 +2669,10 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
 	}
 	params->size >>= 3; /* Convert to bytes. */
 
+	/*if the device exceeds 16MiB, addr_width must be 4*/
+	if ((params->size > 0x1000000) && (nor->addr_width == 3))
+		return -EINVAL;
+
 	/* Fast Read settings. */
 	for (i = 0; i < ARRAY_SIZE(sfdp_bfpt_reads); i++) {
 		const struct sfdp_bfpt_read *rd = &sfdp_bfpt_reads[i];
-- 
1.9.1