mtd: m25p80: return amount of data transferred or error in read/write

Add checking of SPI transfer errors and return them from read/write
functions. Also return the amount of data transferred.

Signed-off-by: Michal Suchanek <hramrach@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Michal Suchanek <hramrach@gmail.com>
Tested-by: Michal Suchanek <hramrach@gmail.com>

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index 3bd75e87ed89ad751e6452ebe8fda399eb25d783..2ef5a6015276cbc845debf08e21f82a6856ec020 100644 (file)
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -81,6 +81,7 @@ static ssize_t m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
        struct spi_transfer t[2] = {};
        struct spi_message m;
        int cmd_sz = m25p_cmdsz(nor);
+       ssize_t ret;
 
        spi_message_init(&m);
 
@@ -98,10 +99,15 @@ static ssize_t m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
        t[1].len = len;
        spi_message_add_tail(&t[1], &m);
 
-       spi_sync(spi, &m);
+       ret = spi_sync(spi, &m);
+       if (ret)
+               return ret;
 
-       *retlen += m.actual_length - cmd_sz;
-       return 0;
+       ret = m.actual_length - cmd_sz;
+       if (ret < 0)
+               return -EIO;
+       *retlen += ret;
+       return ret;
 }
 
 static inline unsigned int m25p80_rx_nbits(struct spi_nor *nor)
@@ -128,13 +134,13 @@ static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
        struct spi_transfer t[2];
        struct spi_message m;
        unsigned int dummy = nor->read_dummy;
+       ssize_t ret;
 
        /* convert the dummy cycles to the number of bytes */
        dummy /= 8;
 
        if (spi_flash_read_supported(spi)) {
                struct spi_flash_read_message msg;
-               int ret;
 
                memset(&msg, 0, sizeof(msg));
 
@@ -151,7 +157,9 @@ static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
 
                ret = spi_flash_read(spi, &msg);
                *retlen = msg.retlen;
-               return ret;
+               if (ret < 0)
+                       return ret;
+               return msg.retlen;
        }
 
        spi_message_init(&m);
@@ -169,10 +177,15 @@ static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
        t[1].len = len;
        spi_message_add_tail(&t[1], &m);
 
-       spi_sync(spi, &m);
+       ret = spi_sync(spi, &m);
+       if (ret)
+               return ret;
 
-       *retlen = m.actual_length - m25p_cmdsz(nor) - dummy;
-       return 0;
+       ret = m.actual_length - m25p_cmdsz(nor) - dummy;
+       if (ret < 0)
+               return -EIO;
+       *retlen += ret;
+       return ret;
 }
 
 /*