[PATCH v6 00/10] Add error checking to spi-nor read and write

[PATCH v6 00/10] Add error checking to spi-nor read and write

[Michal Suchanek]

Hello,

Resending this rebased patchset with ACSII-only To: and updated to use
SIZE_MAX.

Testing wanted, especially for the fsl parts.

Thanks

Michal


Michal Suchanek (10):
  mtd: spi-nor: change return value of read/write
  mtd: m25p80: return amount of data transferred or error in read/write
  mtd: fsl-quadspi: return amount of data read/written or error
  mtd: spi-nor: check return value from read/write
  mtd: spi-nor: stop passing around retlen
  mtd: spi-nor: simplify write loop
  mtd: spi-nor: add read loop
  spi: expose master transfer size limitation.
  spi: fsl-espi: expose maximum transfer size limit
  mtd: m25p80: read in spi_max_transfer_size chunks

 drivers/mtd/devices/m25p80.c      | 31 ++++++++-----
 drivers/mtd/spi-nor/fsl-quadspi.c | 29 ++++++------
 drivers/mtd/spi-nor/spi-nor.c     | 95 +++++++++++++++++++++++++--------------
 drivers/spi/spi-fsl-espi.c        |  6 +++
 include/linux/mtd/spi-nor.h       |  8 ++--
 include/linux/spi/spi.h           | 15 +++++++
 6 files changed, 122 insertions(+), 62 deletions(-)

-- 
2.6.2


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[PATCH v6 03/10] mtd: fsl-quadspi: return amount of data read/written or error

[Michal Suchanek]

Return amount of data read/written or error as read(2)/write(2) does.

Signed-off-by: Michal Suchanek <hramrach@gmail.com>
---
 drivers/mtd/spi-nor/fsl-quadspi.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
index 10d2b59..9beb739 100644
--- a/drivers/mtd/spi-nor/fsl-quadspi.c
+++ b/drivers/mtd/spi-nor/fsl-quadspi.c
@@ -575,7 +575,7 @@ static inline void fsl_qspi_invalid(struct fsl_qspi *q)
 	writel(reg, q->iobase + QUADSPI_MCR);
 }
 
-static int fsl_qspi_nor_write(struct fsl_qspi *q, struct spi_nor *nor,
+static ssize_t fsl_qspi_nor_write(struct fsl_qspi *q, struct spi_nor *nor,
 				u8 opcode, unsigned int to, u32 *txbuf,
 				unsigned count, size_t *retlen)
 {
@@ -604,8 +604,11 @@ static int fsl_qspi_nor_write(struct fsl_qspi *q, struct spi_nor *nor,
 	/* Trigger it */
 	ret = fsl_qspi_runcmd(q, opcode, to, count);
 
-	if (ret == 0 && retlen)
-		*retlen += count;
+	if (ret == 0) {
+		if (retlen)
+			*retlen += count;
+		return count;
+	}
 
 	return ret;
 }
@@ -814,6 +817,8 @@ static int fsl_qspi_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
 	} else if (len > 0) {
 		ret = fsl_qspi_nor_write(q, nor, opcode, 0,
 					(u32 *)buf, len, NULL);
+		if (ret > 0)
+			return 0;
 	} else {
 		dev_err(q->dev, "invalid cmd %d\n", opcode);
 		ret = -EINVAL;
@@ -827,12 +832,12 @@ static ssize_t fsl_qspi_write(struct spi_nor *nor, loff_t to,
 {
 	struct fsl_qspi *q = nor->priv;
 
-	fsl_qspi_nor_write(q, nor, nor->program_opcode, to,
+	ssize_t ret = fsl_qspi_nor_write(q, nor, nor->program_opcode, to,
 				(u32 *)buf, len, retlen);
 
 	/* invalid the data in the AHB buffer. */
 	fsl_qspi_invalid(q);
-	return 0;
+	return ret;
 }
 
 static ssize_t fsl_qspi_read(struct spi_nor *nor, loff_t from,
@@ -878,8 +883,7 @@ static ssize_t fsl_qspi_read(struct spi_nor *nor, loff_t from,
 	memcpy(buf, q->ahb_addr + q->chip_base_addr + from - q->memmap_offs,
 		len);
 
-	*retlen += len;
-	return 0;
+	return len;
 }
 
 static int fsl_qspi_erase(struct spi_nor *nor, loff_t offs)
-- 
2.6.2


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Re: [PATCH v6 03/10] mtd: fsl-quadspi: return amount of data read/written or error

[Han Xu]

On Wed, Dec 02, 2015 at 10:38:19AM +0000, Michal Suchanek wrote:
> Return amount of data read/written or error as read(2)/write(2) does.
> 
> Signed-off-by: Michal Suchanek <hramrach@gmail.com>
> ---
>  drivers/mtd/spi-nor/fsl-quadspi.c | 18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
> index 10d2b59..9beb739 100644
> --- a/drivers/mtd/spi-nor/fsl-quadspi.c
> +++ b/drivers/mtd/spi-nor/fsl-quadspi.c
> @@ -575,7 +575,7 @@ static inline void fsl_qspi_invalid(struct fsl_qspi *q)
>  	writel(reg, q->iobase + QUADSPI_MCR);
>  }
>  
> -static int fsl_qspi_nor_write(struct fsl_qspi *q, struct spi_nor *nor,
> +static ssize_t fsl_qspi_nor_write(struct fsl_qspi *q, struct spi_nor *nor,

conflict with the patch I acked.

https://patchwork.ozlabs.org/patch/545925/

I may change it and test on my side.

>  				u8 opcode, unsigned int to, u32 *txbuf,
>  				unsigned count, size_t *retlen)
>  {
> @@ -604,8 +604,11 @@ static int fsl_qspi_nor_write(struct fsl_qspi *q, struct spi_nor *nor,
>  	/* Trigger it */
>  	ret = fsl_qspi_runcmd(q, opcode, to, count);
>  
> -	if (ret == 0 && retlen)
> -		*retlen += count;
> +	if (ret == 0) {
> +		if (retlen)
> +			*retlen += count;
> +		return count;
> +	}
>  
>  	return ret;
>  }
> @@ -814,6 +817,8 @@ static int fsl_qspi_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
>  	} else if (len > 0) {
>  		ret = fsl_qspi_nor_write(q, nor, opcode, 0,
>  					(u32 *)buf, len, NULL);
> +		if (ret > 0)
> +			return 0;
>  	} else {
>  		dev_err(q->dev, "invalid cmd %d\n", opcode);
>  		ret = -EINVAL;
> @@ -827,12 +832,12 @@ static ssize_t fsl_qspi_write(struct spi_nor *nor, loff_t to,
>  {
>  	struct fsl_qspi *q = nor->priv;
>  
> -	fsl_qspi_nor_write(q, nor, nor->program_opcode, to,
> +	ssize_t ret = fsl_qspi_nor_write(q, nor, nor->program_opcode, to,
>  				(u32 *)buf, len, retlen);
>  
>  	/* invalid the data in the AHB buffer. */
>  	fsl_qspi_invalid(q);
> -	return 0;
> +	return ret;
>  }
>  
>  static ssize_t fsl_qspi_read(struct spi_nor *nor, loff_t from,
> @@ -878,8 +883,7 @@ static ssize_t fsl_qspi_read(struct spi_nor *nor, loff_t from,
>  	memcpy(buf, q->ahb_addr + q->chip_base_addr + from - q->memmap_offs,
>  		len);
>  
> -	*retlen += len;
> -	return 0;
> +	return len;
>  }
>  
>  static int fsl_qspi_erase(struct spi_nor *nor, loff_t offs)
> -- 
> 2.6.2
> 

-- 
Best Regards,

Han "Allen" Xu

Re: [PATCH v6 03/10] mtd: fsl-quadspi: return amount of data read/written or error

[Brian Norris]

On Wed, Dec 02, 2015 at 03:06:28PM -0600, Han Xu wrote:
> On Wed, Dec 02, 2015 at 10:38:19AM +0000, Michal Suchanek wrote:
> > Return amount of data read/written or error as read(2)/write(2) does.
> > 
> > Signed-off-by: Michal Suchanek <hramrach@gmail.com>
> > ---
> >  drivers/mtd/spi-nor/fsl-quadspi.c | 18 +++++++++++-------
> >  1 file changed, 11 insertions(+), 7 deletions(-)
> > 
> > diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
> > index 10d2b59..9beb739 100644
> > --- a/drivers/mtd/spi-nor/fsl-quadspi.c
> > +++ b/drivers/mtd/spi-nor/fsl-quadspi.c
> > @@ -575,7 +575,7 @@ static inline void fsl_qspi_invalid(struct fsl_qspi *q)
> >  	writel(reg, q->iobase + QUADSPI_MCR);
> >  }
> >  
> > -static int fsl_qspi_nor_write(struct fsl_qspi *q, struct spi_nor *nor,
> > +static ssize_t fsl_qspi_nor_write(struct fsl_qspi *q, struct spi_nor *nor,
> 
> conflict with the patch I acked.
> 
> https://patchwork.ozlabs.org/patch/545925/
> 
> I may change it and test on my side.

I'll let you know if I need things rebased. If conflicts are trivial, I
can handle it. But right now, the linked patch (big endian support) is
incomplete (no documentation), and Michal's was just sent today. So it
remains to be seen which will be "ready" first.

Brian

[PATCH v6 02/10] mtd: m25p80: return amount of data transferred or error in read/write

[Michal Suchanek]

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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[PATCH v6 01/10] mtd: spi-nor: change return value of read/write

[Michal Suchanek]

Change the return value of spi-nor device read and write methods to
allow returning amount of data transferred and errors as
read(2)/write(2) does.

Signed-off-by: Michal Suchanek <hramrach@gmail.com>
---

 - avoid compiler warning
---
 drivers/mtd/devices/m25p80.c      | 5 +++--
 drivers/mtd/spi-nor/fsl-quadspi.c | 5 +++--
 include/linux/mtd/spi-nor.h       | 4 ++--
 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index c9c3b7f..6ee3bb3 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -73,7 +73,7 @@ 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;
@@ -101,6 +101,7 @@ static void m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
 	spi_sync(spi, &m);
 
 	*retlen += m.actual_length - cmd_sz;
+	return 0;
 }
 
 static inline unsigned int m25p80_rx_nbits(struct spi_nor *nor)
@@ -119,7 +120,7 @@ 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;
diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
index 54640f1..10d2b59 100644
--- a/drivers/mtd/spi-nor/fsl-quadspi.c
+++ b/drivers/mtd/spi-nor/fsl-quadspi.c
@@ -822,7 +822,7 @@ static int fsl_qspi_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
 	return ret;
 }
 
-static void fsl_qspi_write(struct spi_nor *nor, loff_t to,
+static ssize_t fsl_qspi_write(struct spi_nor *nor, loff_t to,
 		size_t len, size_t *retlen, const u_char *buf)
 {
 	struct fsl_qspi *q = nor->priv;
@@ -832,9 +832,10 @@ static void fsl_qspi_write(struct spi_nor *nor, loff_t to,
 
 	/* invalid the data in the AHB buffer. */
 	fsl_qspi_invalid(q);
+	return 0;
 }
 
-static int fsl_qspi_read(struct spi_nor *nor, loff_t from,
+static ssize_t fsl_qspi_read(struct spi_nor *nor, loff_t from,
 		size_t len, size_t *retlen, u_char *buf)
 {
 	struct fsl_qspi *q = nor->priv;
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 7bed974..6080701 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -171,9 +171,9 @@ struct spi_nor {
 	int (*read_reg)(struct spi_nor *nor, u8 opcode, u8 *buf, int len);
 	int (*write_reg)(struct spi_nor *nor, u8 opcode, u8 *buf, int len);
 
-	int (*read)(struct spi_nor *nor, loff_t from,
+	ssize_t (*read)(struct spi_nor *nor, loff_t from,
 			size_t len, size_t *retlen, u_char *read_buf);
-	void (*write)(struct spi_nor *nor, loff_t to,
+	ssize_t (*write)(struct spi_nor *nor, loff_t to,
 			size_t len, size_t *retlen, const u_char *write_buf);
 	int (*erase)(struct spi_nor *nor, loff_t offs);
 
-- 
2.6.2


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[PATCH v6 07/10] mtd: spi-nor: add read loop

[Michal Suchanek]

mtdblock and ubi do not handle the situation when read returns less data
than requested. Loop in spi-nor until buffer is filled or an error is
returned.

Signed-off-by: Michal Suchanek <hramrach@gmail.com>

---
 - use WARN_ON rather than BUG_ON
---
 drivers/mtd/spi-nor/spi-nor.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 115c123..ded79ae 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -907,14 +907,22 @@ static int spi_nor_read(struct mtd_info *mtd, loff_t from, size_t len,
 	if (ret)
 		return ret;
 
-	ret = nor->read(nor, from, len, buf);
+	while (len) {
+		ret = nor->read(nor, from, len, buf);
+		if (ret <= 0)
+			goto read_err;
+
+		WARN_ON(ret > len);
+		*retlen += ret;
+		buf += ret;
+		from += ret;
+		len -= ret;
+	}
+	ret = 0;
 
+read_err:
 	spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_READ);
-	if (ret < 0)
-		return ret;
-
-	*retlen += ret;
-	return 0;
+	return ret;
 }
 
 static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
-- 
2.6.2


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[PATCH v6 04/10] mtd: spi-nor: check return value from read/write

[Michal Suchanek]

SPI NOR hardware drivers now return useful value from their read/write
functions so check them.

Signed-off-by: Michal Suchanek <hramrach@gmail.com>
---
 drivers/mtd/spi-nor/spi-nor.c | 50 +++++++++++++++++++++++++++++++------------
 1 file changed, 36 insertions(+), 14 deletions(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index b7c038c..5f91bfa 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -910,7 +910,10 @@ static int spi_nor_read(struct mtd_info *mtd, loff_t from, size_t len,
 	ret = nor->read(nor, from, len, retlen, buf);
 
 	spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_READ);
-	return ret;
+	if (ret < 0)
+		return ret;
+
+	return 0;
 }
 
 static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
@@ -936,10 +939,14 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
 		nor->program_opcode = SPINOR_OP_BP;
 
 		/* write one byte. */
-		nor->write(nor, to, 1, retlen, buf);
+		ret = nor->write(nor, to, 1, retlen, buf);
+		if (ret < 0)
+			goto sst_write_err;
+		WARN(ret != 1, "While writing 1 byte written %i bytes\n",
+		     (int)ret);
 		ret = spi_nor_wait_till_ready(nor);
 		if (ret)
-			goto time_out;
+			goto sst_write_err;
 	}
 	to += actual;
 
@@ -948,10 +955,14 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
 		nor->program_opcode = SPINOR_OP_AAI_WP;
 
 		/* write two bytes. */
-		nor->write(nor, to, 2, retlen, buf + actual);
+		ret = nor->write(nor, to, 2, retlen, buf + actual);
+		if (ret < 0)
+			goto sst_write_err;
+		WARN(ret != 2, "While writing 2 bytes written %i bytes\n",
+		     (int)ret);
 		ret = spi_nor_wait_till_ready(nor);
 		if (ret)
-			goto time_out;
+			goto sst_write_err;
 		to += 2;
 		nor->sst_write_second = true;
 	}
@@ -960,21 +971,24 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
 	write_disable(nor);
 	ret = spi_nor_wait_till_ready(nor);
 	if (ret)
-		goto time_out;
+		goto sst_write_err;
 
 	/* Write out trailing byte if it exists. */
 	if (actual != len) {
 		write_enable(nor);
 
 		nor->program_opcode = SPINOR_OP_BP;
-		nor->write(nor, to, 1, retlen, buf + actual);
-
+		ret = nor->write(nor, to, 1, retlen, buf + actual);
+		if (ret < 0)
+			goto sst_write_err;
+		WARN(ret != 1, "While writing 1 byte written %i bytes\n",
+		     (int)ret);
 		ret = spi_nor_wait_till_ready(nor);
 		if (ret)
-			goto time_out;
+			goto sst_write_err;
 		write_disable(nor);
 	}
-time_out:
+sst_write_err:
 	spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_WRITE);
 	return ret;
 }
@@ -1003,14 +1017,18 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 
 	/* do all the bytes fit onto one page? */
 	if (page_offset + len <= nor->page_size) {
-		nor->write(nor, to, len, retlen, buf);
+		ret = nor->write(nor, to, len, retlen, buf);
+		if (ret < 0)
+			goto write_err;
 	} else {
 		/* the size of data remaining on the first page */
 		page_size = nor->page_size - page_offset;
-		nor->write(nor, to, page_size, retlen, buf);
+		ret = nor->write(nor, to, page_size, retlen, buf);
+		if (ret < 0)
+			goto write_err;
 
 		/* write everything in nor->page_size chunks */
-		for (i = page_size; i < len; i += page_size) {
+		for (i = ret; i < len; ) {
 			page_size = len - i;
 			if (page_size > nor->page_size)
 				page_size = nor->page_size;
@@ -1021,7 +1039,11 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 
 			write_enable(nor);
 
-			nor->write(nor, to + i, page_size, retlen, buf + i);
+			ret = nor->write(nor, to + i, page_size, retlen,
+					 buf + i);
+			if (ret < 0)
+				goto write_err;
+			i += ret;
 		}
 	}
 
-- 
2.6.2


______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

[PATCH v6 05/10] mtd: spi-nor: stop passing around retlen

[Michal Suchanek]

Do not pass retlen to hardware driver read/write functions. Update it in
spi-nor generic driver instead.

Signed-off-by: Michal Suchanek <hramrach@gmail.com>
---
 drivers/mtd/devices/m25p80.c      |  6 ++----
 drivers/mtd/spi-nor/fsl-quadspi.c | 16 ++++++----------
 drivers/mtd/spi-nor/spi-nor.c     | 21 +++++++++++++--------
 include/linux/mtd/spi-nor.h       |  4 ++--
 4 files changed, 23 insertions(+), 24 deletions(-)

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index fc694fd..58ecfa4 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -74,7 +74,7 @@ static int m25p80_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
 }
 
 static ssize_t m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
-			size_t *retlen, const u_char *buf)
+			    const u_char *buf)
 {
 	struct m25p *flash = nor->priv;
 	struct spi_device *spi = flash->spi;
@@ -106,7 +106,6 @@ static ssize_t m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
 	ret = m.actual_length - cmd_sz;
 	if (ret < 0)
 		return -EIO;
-	*retlen += ret;
 	return ret;
 }
 
@@ -127,7 +126,7 @@ static inline unsigned int m25p80_rx_nbits(struct spi_nor *nor)
  * may be any size provided it is within the physical boundaries.
  */
 static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
-			size_t *retlen, u_char *buf)
+			   u_char *buf)
 {
 	struct m25p *flash = nor->priv;
 	struct spi_device *spi = flash->spi;
@@ -161,7 +160,6 @@ static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
 	ret = m.actual_length - m25p_cmdsz(nor) - dummy;
 	if (ret < 0)
 		return -EIO;
-	*retlen += ret;
 	return ret;
 }
 
diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
index 9beb739..7491fbb 100644
--- a/drivers/mtd/spi-nor/fsl-quadspi.c
+++ b/drivers/mtd/spi-nor/fsl-quadspi.c
@@ -577,7 +577,7 @@ static inline void fsl_qspi_invalid(struct fsl_qspi *q)
 
 static ssize_t fsl_qspi_nor_write(struct fsl_qspi *q, struct spi_nor *nor,
 				u8 opcode, unsigned int to, u32 *txbuf,
-				unsigned count, size_t *retlen)
+				unsigned count)
 {
 	int ret, i, j;
 	u32 tmp;
@@ -604,11 +604,8 @@ static ssize_t fsl_qspi_nor_write(struct fsl_qspi *q, struct spi_nor *nor,
 	/* Trigger it */
 	ret = fsl_qspi_runcmd(q, opcode, to, count);
 
-	if (ret == 0) {
-		if (retlen)
-			*retlen += count;
+	if (ret == 0)
 		return count;
-	}
 
 	return ret;
 }
@@ -816,7 +813,7 @@ static int fsl_qspi_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
 
 	} else if (len > 0) {
 		ret = fsl_qspi_nor_write(q, nor, opcode, 0,
-					(u32 *)buf, len, NULL);
+					(u32 *)buf, len);
 		if (ret > 0)
 			return 0;
 	} else {
@@ -828,12 +825,11 @@ static int fsl_qspi_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
 }
 
 static ssize_t fsl_qspi_write(struct spi_nor *nor, loff_t to,
-		size_t len, size_t *retlen, const u_char *buf)
+			      size_t len, const u_char *buf)
 {
 	struct fsl_qspi *q = nor->priv;
-
 	ssize_t ret = fsl_qspi_nor_write(q, nor, nor->program_opcode, to,
-				(u32 *)buf, len, retlen);
+					 (u32 *)buf, len);
 
 	/* invalid the data in the AHB buffer. */
 	fsl_qspi_invalid(q);
@@ -841,7 +837,7 @@ static ssize_t fsl_qspi_write(struct spi_nor *nor, loff_t to,
 }
 
 static ssize_t fsl_qspi_read(struct spi_nor *nor, loff_t from,
-		size_t len, size_t *retlen, u_char *buf)
+			     size_t len, u_char *buf)
 {
 	struct fsl_qspi *q = nor->priv;
 	u8 cmd = nor->read_opcode;
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 5f91bfa..3d02803 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -907,12 +907,13 @@ static int spi_nor_read(struct mtd_info *mtd, loff_t from, size_t len,
 	if (ret)
 		return ret;
 
-	ret = nor->read(nor, from, len, retlen, buf);
+	ret = nor->read(nor, from, len, buf);
 
 	spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_READ);
 	if (ret < 0)
 		return ret;
 
+	*retlen += ret;
 	return 0;
 }
 
@@ -939,7 +940,7 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
 		nor->program_opcode = SPINOR_OP_BP;
 
 		/* write one byte. */
-		ret = nor->write(nor, to, 1, retlen, buf);
+		ret = nor->write(nor, to, 1, buf);
 		if (ret < 0)
 			goto sst_write_err;
 		WARN(ret != 1, "While writing 1 byte written %i bytes\n",
@@ -955,7 +956,7 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
 		nor->program_opcode = SPINOR_OP_AAI_WP;
 
 		/* write two bytes. */
-		ret = nor->write(nor, to, 2, retlen, buf + actual);
+		ret = nor->write(nor, to, 2, buf + actual);
 		if (ret < 0)
 			goto sst_write_err;
 		WARN(ret != 2, "While writing 2 bytes written %i bytes\n",
@@ -978,7 +979,7 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
 		write_enable(nor);
 
 		nor->program_opcode = SPINOR_OP_BP;
-		ret = nor->write(nor, to, 1, retlen, buf + actual);
+		ret = nor->write(nor, to, 1, buf + actual);
 		if (ret < 0)
 			goto sst_write_err;
 		WARN(ret != 1, "While writing 1 byte written %i bytes\n",
@@ -987,8 +988,10 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
 		if (ret)
 			goto sst_write_err;
 		write_disable(nor);
+		actual += 1;
 	}
 sst_write_err:
+	*retlen += actual;
 	spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_WRITE);
 	return ret;
 }
@@ -1017,15 +1020,17 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 
 	/* do all the bytes fit onto one page? */
 	if (page_offset + len <= nor->page_size) {
-		ret = nor->write(nor, to, len, retlen, buf);
+		ret = nor->write(nor, to, len, buf);
 		if (ret < 0)
 			goto write_err;
+		*retlen += ret;
 	} else {
 		/* the size of data remaining on the first page */
 		page_size = nor->page_size - page_offset;
-		ret = nor->write(nor, to, page_size, retlen, buf);
+		ret = nor->write(nor, to, page_size, buf);
 		if (ret < 0)
 			goto write_err;
+		*retlen += ret;
 
 		/* write everything in nor->page_size chunks */
 		for (i = ret; i < len; ) {
@@ -1039,10 +1044,10 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 
 			write_enable(nor);
 
-			ret = nor->write(nor, to + i, page_size, retlen,
-					 buf + i);
+			ret = nor->write(nor, to + i, page_size, buf + i);
 			if (ret < 0)
 				goto write_err;
+			*retlen += ret;
 			i += ret;
 		}
 	}
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 6080701..c4b059b 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -172,9 +172,9 @@ struct spi_nor {
 	int (*write_reg)(struct spi_nor *nor, u8 opcode, u8 *buf, int len);
 
 	ssize_t (*read)(struct spi_nor *nor, loff_t from,
-			size_t len, size_t *retlen, u_char *read_buf);
+			size_t len, u_char *read_buf);
 	ssize_t (*write)(struct spi_nor *nor, loff_t to,
-			size_t len, size_t *retlen, const u_char *write_buf);
+			size_t len, const u_char *write_buf);
 	int (*erase)(struct spi_nor *nor, loff_t offs);
 
 	int (*flash_lock)(struct spi_nor *nor, loff_t ofs, uint64_t len);
-- 
2.6.2


______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

[PATCH v6 06/10] mtd: spi-nor: simplify write loop

[Michal Suchanek]

The spi-nor write loop assumes that what is passed to the hardware
driver write() is what gets written.

When write() writes less than page size at once data is dropped on the
floor. Check the amount of data writen and exit if it does not match
requested amount.

Signed-off-by: Michal Suchanek <hramrach@gmail.com>

---

 - add warning when writing incomplete pages
 - refuse to continue writing when full page was not written
---
 drivers/mtd/spi-nor/spi-nor.c | 58 +++++++++++++++++++------------------------
 1 file changed, 25 insertions(+), 33 deletions(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 3d02803..115c123 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -1005,8 +1005,8 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 	size_t *retlen, const u_char *buf)
 {
 	struct spi_nor *nor = mtd_to_spi_nor(mtd);
-	u32 page_offset, page_size, i;
-	int ret;
+	size_t page_offset, page_remain, i;
+	ssize_t ret;
 
 	dev_dbg(nor->dev, "to 0x%08x, len %zd\n", (u32)to, len);
 
@@ -1014,45 +1014,37 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 	if (ret)
 		return ret;
 
-	write_enable(nor);
-
-	page_offset = to & (nor->page_size - 1);
+	for (i = 0; i < len; ) {
+		ssize_t written;
 
-	/* do all the bytes fit onto one page? */
-	if (page_offset + len <= nor->page_size) {
-		ret = nor->write(nor, to, len, buf);
-		if (ret < 0)
-			goto write_err;
-		*retlen += ret;
-	} else {
+		page_offset = to & (nor->page_size - 1);
+		WARN_ONCE(page_offset,
+			  "Writing at offset %zu into a NOR page. Writing partial pages may decrease reliability and increase wear of NOR flash.",
+			  page_offset);
 		/* the size of data remaining on the first page */
-		page_size = nor->page_size - page_offset;
-		ret = nor->write(nor, to, page_size, buf);
+		page_remain = min_t(size_t,
+				    nor->page_size - page_offset, len - i);
+
+		write_enable(nor);
+		ret = nor->write(nor, to + i, page_remain, buf + i);
 		if (ret < 0)
 			goto write_err;
-		*retlen += ret;
-
-		/* write everything in nor->page_size chunks */
-		for (i = ret; i < len; ) {
-			page_size = len - i;
-			if (page_size > nor->page_size)
-				page_size = nor->page_size;
-
-			ret = spi_nor_wait_till_ready(nor);
-			if (ret)
-				goto write_err;
+		written = ret;
 
-			write_enable(nor);
-
-			ret = nor->write(nor, to + i, page_size, buf + i);
-			if (ret < 0)
-				goto write_err;
-			*retlen += ret;
-			i += ret;
+		ret = spi_nor_wait_till_ready(nor);
+		if (ret)
+			goto write_err;
+		*retlen += written;
+		i += written;
+		if (written != page_remain) {
+			dev_err(nor->dev,
+				"While writing %zu bytes written %zd bytes\n",
+				page_remain, written);
+			ret = -EIO;
+			goto write_err;
 		}
 	}
 
-	ret = spi_nor_wait_till_ready(nor);
 write_err:
 	spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_WRITE);
 	return ret;
-- 
2.6.2


______________________________________________________
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http://lists.infradead.org/mailman/listinfo/linux-mtd/

Re: [PATCH v6 06/10] mtd: spi-nor: simplify write loop

[Han Xu]

On Wed, Dec 02, 2015 at 10:38:20AM +0000, Michal Suchanek wrote:
> The spi-nor write loop assumes that what is passed to the hardware
> driver write() is what gets written.
> 
> When write() writes less than page size at once data is dropped on the
> floor. Check the amount of data writen and exit if it does not match
> requested amount.
> 
> Signed-off-by: Michal Suchanek <hramrach-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> 
> ---
> 
>  - add warning when writing incomplete pages
>  - refuse to continue writing when full page was not written
> ---
>  drivers/mtd/spi-nor/spi-nor.c | 58 +++++++++++++++++++------------------------
>  1 file changed, 25 insertions(+), 33 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index 3d02803..115c123 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -1005,8 +1005,8 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
>  	size_t *retlen, const u_char *buf)
>  {
>  	struct spi_nor *nor = mtd_to_spi_nor(mtd);
> -	u32 page_offset, page_size, i;
> -	int ret;
> +	size_t page_offset, page_remain, i;
> +	ssize_t ret;
>  
>  	dev_dbg(nor->dev, "to 0x%08x, len %zd\n", (u32)to, len);
>  
> @@ -1014,45 +1014,37 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
>  	if (ret)
>  		return ret;
>  
> -	write_enable(nor);
> -
> -	page_offset = to & (nor->page_size - 1);
> +	for (i = 0; i < len; ) {
> +		ssize_t written;
>  
> -	/* do all the bytes fit onto one page? */
> -	if (page_offset + len <= nor->page_size) {
> -		ret = nor->write(nor, to, len, buf);
> -		if (ret < 0)
> -			goto write_err;
> -		*retlen += ret;
> -	} else {
> +		page_offset = to & (nor->page_size - 1);
> +		WARN_ONCE(page_offset,
> +			  "Writing at offset %zu into a NOR page. Writing partial pages may decrease reliability and increase wear of NOR flash.",
> +			  page_offset);
>  		/* the size of data remaining on the first page */
> -		page_size = nor->page_size - page_offset;
> -		ret = nor->write(nor, to, page_size, buf);
> +		page_remain = min_t(size_t,
> +				    nor->page_size - page_offset, len - i);
> +
> +		write_enable(nor);
> +		ret = nor->write(nor, to + i, page_remain, buf + i);

Previous implementation was trying to write nor->page_size byte data in
each loop, except the first and last loop, if possible. But this change
may write only (nor->page_size - page_offset) in each loop, for the
worst case, if page_offset equals nor->page_size -1, it writes byte by
byte.

>  		if (ret < 0)
>  			goto write_err;
> -		*retlen += ret;
> -
> -		/* write everything in nor->page_size chunks */
> -		for (i = ret; i < len; ) {
> -			page_size = len - i;
> -			if (page_size > nor->page_size)
> -				page_size = nor->page_size;
> -
> -			ret = spi_nor_wait_till_ready(nor);
> -			if (ret)
> -				goto write_err;
> +		written = ret;
>  
> -			write_enable(nor);
> -
> -			ret = nor->write(nor, to + i, page_size, buf + i);
> -			if (ret < 0)
> -				goto write_err;
> -			*retlen += ret;
> -			i += ret;
> +		ret = spi_nor_wait_till_ready(nor);
> +		if (ret)
> +			goto write_err;
> +		*retlen += written;
> +		i += written;
> +		if (written != page_remain) {
> +			dev_err(nor->dev,
> +				"While writing %zu bytes written %zd bytes\n",
> +				page_remain, written);
> +			ret = -EIO;
> +			goto write_err;
>  		}
>  	}
>  
> -	ret = spi_nor_wait_till_ready(nor);
>  write_err:
>  	spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_WRITE);
>  	return ret;
> -- 
> 2.6.2
> 

-- 
Best Regards,

Han "Allen" Xu

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Re: [PATCH v6 06/10] mtd: spi-nor: simplify write loop

[Michal Suchanek]

On 15 December 2015 at 21:22, Han Xu <han.xu@freescale.com> wrote:
> On Wed, Dec 02, 2015 at 10:38:20AM +0000, Michal Suchanek wrote:
>> The spi-nor write loop assumes that what is passed to the hardware
>> driver write() is what gets written.
>>
>> When write() writes less than page size at once data is dropped on the
>> floor. Check the amount of data writen and exit if it does not match
>> requested amount.
>>
>> Signed-off-by: Michal Suchanek <hramrach@gmail.com>
>>
>> ---
>>
>>  - add warning when writing incomplete pages
>>  - refuse to continue writing when full page was not written
>> ---
>>  drivers/mtd/spi-nor/spi-nor.c | 58 +++++++++++++++++++------------------------
>>  1 file changed, 25 insertions(+), 33 deletions(-)
>>
>> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
>> index 3d02803..115c123 100644
>> --- a/drivers/mtd/spi-nor/spi-nor.c
>> +++ b/drivers/mtd/spi-nor/spi-nor.c
>> @@ -1005,8 +1005,8 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
>>       size_t *retlen, const u_char *buf)
>>  {
>>       struct spi_nor *nor = mtd_to_spi_nor(mtd);
>> -     u32 page_offset, page_size, i;
>> -     int ret;
>> +     size_t page_offset, page_remain, i;
>> +     ssize_t ret;
>>
>>       dev_dbg(nor->dev, "to 0x%08x, len %zd\n", (u32)to, len);
>>
>> @@ -1014,45 +1014,37 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
>>       if (ret)
>>               return ret;
>>
>> -     write_enable(nor);
>> -
>> -     page_offset = to & (nor->page_size - 1);
>> +     for (i = 0; i < len; ) {
>> +             ssize_t written;
>>
>> -     /* do all the bytes fit onto one page? */
>> -     if (page_offset + len <= nor->page_size) {
>> -             ret = nor->write(nor, to, len, buf);
>> -             if (ret < 0)
>> -                     goto write_err;
>> -             *retlen += ret;
>> -     } else {
>> +             page_offset = to & (nor->page_size - 1);
>> +             WARN_ONCE(page_offset,
>> +                       "Writing at offset %zu into a NOR page. Writing partial pages may decrease reliability and increase wear of NOR flash.",
>> +                       page_offset);
>>               /* the size of data remaining on the first page */
>> -             page_size = nor->page_size - page_offset;
>> -             ret = nor->write(nor, to, page_size, buf);
>> +             page_remain = min_t(size_t,
>> +                                 nor->page_size - page_offset, len - i);
>> +
>> +             write_enable(nor);
>> +             ret = nor->write(nor, to + i, page_remain, buf + i);
>
> Previous implementation was trying to write nor->page_size byte data in
> each loop, except the first and last loop, if possible. But this change
> may write only (nor->page_size - page_offset) in each loop, for the
> worst case, if page_offset equals nor->page_size -1, it writes byte by
> byte.

Indeed, there should be to + i when determining page_offset.

Thanks

Michal

[PATCH v6 08/10] spi: expose master transfer size limitation.

[Michal Suchanek]

On some SPI controllers it is not feasible to transfer arbitrary amount
of data at once.

When the limit on transfer size is a few kilobytes at least it makes
sense to use the SPI hardware rather than reverting to gpio driver.

The protocol drivers need a way to check that they do not sent overly
long messages, though.

Signed-off-by: Michal Suchanek <hramrach@gmail.com>

---

 - return SIZE_MAX when no limit is known
---
 include/linux/spi/spi.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index cce80e6..3eebc6c 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -425,6 +425,12 @@ struct spi_master {
 #define SPI_MASTER_MUST_RX      BIT(3)		/* requires rx */
 #define SPI_MASTER_MUST_TX      BIT(4)		/* requires tx */
 
+	/*
+	 * on some hardware transfer size may be constrained
+	 * the limit may depend on device transfer settings
+	 */
+	size_t (*max_transfer_size)(struct spi_device *spi);
+
 	/* lock and mutex for SPI bus locking */
 	spinlock_t		bus_lock_spinlock;
 	struct mutex		bus_lock_mutex;
@@ -832,6 +838,15 @@ extern int spi_async(struct spi_device *spi, struct spi_message *message);
 extern int spi_async_locked(struct spi_device *spi,
 			    struct spi_message *message);
 
+static inline size_t
+spi_max_transfer_size(struct spi_device *spi)
+{
+	struct spi_master *master = spi->master;
+	if (!master->max_transfer_size)
+		return SIZE_MAX;
+	return master->max_transfer_size(spi);
+}
+
 /*---------------------------------------------------------------------------*/
 
 /* All these synchronous SPI transfer routines are utilities layered
-- 
2.6.2


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[PATCH v6 09/10] spi: fsl-espi: expose maximum transfer size limit

[Michal Suchanek]

The fsl-espi hardware can trasfer at most 64K data so report teh
limitation.

Based on patch by Heiner Kallweit <hkallweit1@gmail.com>

CC: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Michal Suchanek <hramrach@gmail.com>
---
 drivers/spi/spi-fsl-espi.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c
index c27124a..7fd6a4c 100644
--- a/drivers/spi/spi-fsl-espi.c
+++ b/drivers/spi/spi-fsl-espi.c
@@ -643,6 +643,11 @@ static int fsl_espi_runtime_resume(struct device *dev)
 }
 #endif
 
+static size_t fsl_espi_max_transfer_size(struct spi_device *spi)
+{
+	return SPCOM_TRANLEN_MAX;
+}
+
 static struct spi_master * fsl_espi_probe(struct device *dev,
 		struct resource *mem, unsigned int irq)
 {
@@ -670,6 +675,7 @@ static struct spi_master * fsl_espi_probe(struct device *dev,
 	master->cleanup = fsl_espi_cleanup;
 	master->transfer_one_message = fsl_espi_do_one_msg;
 	master->auto_runtime_pm = true;
+	master->max_transfer_size = fsl_espi_max_transfer_size;
 
 	mpc8xxx_spi = spi_master_get_devdata(master);
 
-- 
2.6.2


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[PATCH v6 10/10] mtd: m25p80: read in spi_max_transfer_size chunks

[Michal Suchanek]

Take into account transfer size limitation of SPI master.

Signed-off-by: Michal Suchanek <hramrach@gmail.com>

---

 - update for: return SIZE_MAX when no limit is known
---
 drivers/mtd/devices/m25p80.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index 58ecfa4..f36ffc6 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -150,7 +150,7 @@ static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
 
 	t[1].rx_buf = buf;
 	t[1].rx_nbits = m25p80_rx_nbits(nor);
-	t[1].len = len;
+	t[1].len = min_t(size_t, len, spi_max_transfer_size(spi));
 	spi_message_add_tail(&t[1], &m);
 
 	ret = spi_sync(spi, &m);
-- 
2.6.2


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