[PATCH v2 2/6] mtd: m25p80: Add read/write error check and return

[Michal Suchanek]

Add checking of SPI transfer errors and return them from read/write
functions.

Signed-off-by: Michal Suchanek <hramrach at gmail.com>
---
 drivers/mtd/devices/m25p80.c | 31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index d313f948b..c93bc41 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -75,7 +75,7 @@ static int m25p80_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len,
 	return spi_write(spi, flash->command, len + 1);
 }
 
-static void m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
+static ssize_t m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
 			size_t *retlen, const u_char *buf)
 {
 	struct m25p *flash = nor->priv;
@@ -83,6 +83,7 @@ static void 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);
 
@@ -100,9 +101,15 @@ static void 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;
+	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)
@@ -121,7 +128,7 @@ static inline unsigned int m25p80_rx_nbits(struct spi_nor *nor)
  * Read an address range from the nor chip.  The address range
  * may be any size provided it is within the physical boundaries.
  */
-static int m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
+static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
 			size_t *retlen, u_char *buf)
 {
 	struct m25p *flash = nor->priv;
@@ -129,6 +136,7 @@ static int 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;
@@ -148,10 +156,15 @@ static int 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;
 }
 
 static int m25p80_erase(struct spi_nor *nor, loff_t offset)
@@ -165,9 +178,7 @@ static int m25p80_erase(struct spi_nor *nor, loff_t offset)
 	flash->command[0] = nor->erase_opcode;
 	m25p_addr2cmd(nor, offset, flash->command);
 
-	spi_write(flash->spi, flash->command, m25p_cmdsz(nor));
-
-	return 0;
+	return spi_write(flash->spi, flash->command, m25p_cmdsz(nor));
 }
 
 /*
-- 
2.1.4