From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Thu, 15 Aug 2019 11:32:52 +0300
Subject: mtd: spi-nor: Fix an error code in spi_nor_read_raw()
References: bsc#1175413

Git-commit: 3e9e38d918bd01068b5ccba17d69a8ae9bf56142
Patch-mainline: v5.4-rc1

The problem is that if "ret" is negative then when we check if
"ret > len", that condition is going to be true because of type
promotion.  So this patch re-orders the code to check for negatives
first and preserve those error codes.

Fixes: f384b352cbf0 ("mtd: spi-nor: parse Serial Flash Discoverable Parameters (SFDP) tables")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de>
---
 drivers/mtd/spi-nor/spi-nor.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -1806,12 +1806,12 @@ static int spi_nor_read_sfdp(struct spi_
 
 	while (len) {
 		ret = nor->read(nor, addr, len, (u8 *)buf);
+		if (ret < 0)
+			goto read_err;
 		if (!ret || ret > len) {
 			ret = -EIO;
 			goto read_err;
 		}
-		if (ret < 0)
-			goto read_err;
 
 		buf += ret;
 		addr += ret;