[PATCH v5 02/10] mtd: m25p80: return amount of data transferred or error in read/write

From: Michal Suchanek <hramrach@gmail.com>
To: Heiner Kallweit <hkallweit1@gmail.com>,
	David Woodhouse <dwmw2@infradead.org>,
	Brian Norris <computersforpeace@gmail.com>,
	Han Xu <han.xu@freescale.com>, Mark Brown <broonie@kernel.org>,
	Michal Suchanek <hramrach@gmail.com>,
	Boris Brezillon <boris.brezillon@free-electrons.com>,
	Javier Martinez Canillas <javier@osg.samsung.com>,
	Stephen Warren <swarren@nvidia.com>,
	"Andrew F. Davis" <afd@ti.com>, Marek Vasut <marex@denx.de>,
	"Rafał Miłecki" <zajec5@gmail.com>,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	Gabor Juhos <juhosg@openwrt.org>,
	"Bean Huo 霍斌斌 " <beanhuo@micron.com>,
	Furquan Shaikh <furquan@google.com>,
	linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
	linux-spi@vger.kernel.org,
Subject: [PATCH v5 02/10] mtd: m25p80: return amount of data transferred or error in read/write
Date: 1 Dec 2015 16:51:04 -0000	[thread overview]
Message-ID: <addb82044e8f8472ac0d02bd08ee5dca1a186117.1448988089.git.hramrach@gmail.com> (raw)
In-Reply-To: <cover.1448988089.git.hramrach@gmail.com>

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>
---
 drivers/mtd/devices/m25p80.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index 6ee3bb3..fc694fd 100644
--- 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)
@@ -128,6 +134,7 @@ 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;
@@ -147,10 +154,15 @@ 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;
 }
 
 /*
-- 
2.6.2


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