mtd: spi-nor: Check the return value from read_sr()

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>

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 3b2460e..7e5051e 100644 (file)
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -478,11 +478,13 @@ static int stm_is_locked_sr(struct spi_nor *nor, loff_t ofs, uint64_t len,
 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) {
@@ -528,11 +530,13 @@ static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
 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, status_old, ofs - mtd->erasesize,
@@ -1032,6 +1036,8 @@ static int macronix_quad_enable(struct spi_nor *nor)
        int ret, val;
 
        val = read_sr(nor);
+       if (val < 0)
+               return val;
        write_enable(nor);
 
        write_sr(nor, val | SR_QUAD_EN_MX);