From d05c68e35f42a46b352d2a4bdaef9954c946e20a Mon Sep 17 00:00:00 2001
From: Fabio Estevam <fabio.estevam@freescale.com>
Date: Fri, 20 Nov 2015 16:26:11 -0200
Subject: [PATCH 085/113] mtd: spi-nor: Check the return value from read_sr()

[context adjustment]

We should better check the return value from read_sr() and
propagate it in the case of error.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Integrated-by: Jiang Yutang <yutang.jiang@nxp.com>
---
 drivers/mtd/spi-nor/spi-nor.c |   10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -479,11 +479,13 @@ static int stm_is_locked_sr(struct spi_n
 static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
 {
 	struct mtd_info *mtd = &nor->mtd;
-	u8 status_old, status_new;
+	int status_old, status_new;
 	u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
 	u8 shift = ffs(mask) - 1, pow, val;
 
 	status_old = read_sr(nor);
+	if (status_old < 0)
+		return status_old;
 
 	/* SPI NOR always locks to the end */
 	if (ofs + len != mtd->size) {
@@ -529,11 +531,13 @@ static int stm_lock(struct spi_nor *nor,
 static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
 {
 	struct mtd_info *mtd = &nor->mtd;
-	uint8_t status_old, status_new;
+	int status_old, status_new;
 	u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
 	u8 shift = ffs(mask) - 1, pow, val;
 
 	status_old = read_sr(nor);
+	if (status_old < 0)
+		return status_old;
 
 	/* Cannot unlock; would unlock larger region than requested */
 	if (stm_is_locked_sr(nor, ofs - mtd->erasesize, mtd->erasesize,
@@ -1044,6 +1048,8 @@ static int macronix_quad_enable(struct s
 	int ret, val;
 
 	val = read_sr(nor);
+	if (val < 0)
+		return val;
 	write_enable(nor);
 
 	write_sr(nor, val | SR_QUAD_EN_MX);
