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* [PATCH v4 0/2] mtd: spi-nor: use spi-mem dirmap API
@ 2020-01-27 20:23 Sergei Shtylyov
  2020-01-27 20:28 ` [PATCH v4 1/2] mtd: spi-nor: split spi_nor_spimem_xfer_data() Sergei Shtylyov
  2020-01-27 20:29 ` [PATCH v4 2/2] mtd: spi-nor: use spi-mem dirmap API Sergei Shtylyov
  0 siblings, 2 replies; 8+ messages in thread
From: Sergei Shtylyov @ 2020-01-27 20:23 UTC (permalink / raw)
  To: Tudor Ambarus, Miquel Raynal, Richard Weinberger,
	Vignesh Raghavendra, linux-mtd

Here's a set of 2 patches against the 'spi-nor/next' branch of the MTD 'linux.git'
repo. We make use of the spi-mem direct mapping API to let advanced controllers
optimize read/write operations when they support direct mapping. Previous versions
only had a single patch, in this version a preparatory patch was added.

The previous posting had garbage in the subject, so resending with this fixed...)

[1/2] mtd: spi-nor: split spi_nor_spimem_xfer_data()
[2/2] mtd: spi-nor: use spi-mem dirmap API

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

^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH v4 1/2] mtd: spi-nor: split spi_nor_spimem_xfer_data()
  2020-01-27 20:23 [PATCH v4 0/2] mtd: spi-nor: use spi-mem dirmap API Sergei Shtylyov
@ 2020-01-27 20:28 ` Sergei Shtylyov
  2020-01-28  6:50   ` Boris Brezillon
  2020-02-16 22:40   ` Tudor.Ambarus
  2020-01-27 20:29 ` [PATCH v4 2/2] mtd: spi-nor: use spi-mem dirmap API Sergei Shtylyov
  1 sibling, 2 replies; 8+ messages in thread
From: Sergei Shtylyov @ 2020-01-27 20:28 UTC (permalink / raw)
  To: Tudor Ambarus, Miquel Raynal, Richard Weinberger,
	Vignesh Raghavendra, linux-mtd

spi_nor_spimem_xfer_data() being a helper function for the data reads/
writes contains 3 fragments that depend on the data direction; and I'm
going to add another one to call the SPI dirmap API...
I think this function should be split so that the common fragments are
put into 2 functions, spi_nor_spimem_bounce() and spi_nor_spimem_exec_op()
called from spi_nor_spimem_{read|write}_data(), and the data direction
dependent bits moved back into those read/write functions -- that way we
would be able to avoid *goto*s otherwise needed in the next patch adding
the  SPI dirmap support...

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

---
Changes in version 4:
- new patch.

 drivers/mtd/spi-nor/spi-nor.c |   91 +++++++++++++++++++++++-------------------
 1 file changed, 51 insertions(+), 40 deletions(-)

Index: linux/drivers/mtd/spi-nor/spi-nor.c
===================================================================
--- linux.orig/drivers/mtd/spi-nor/spi-nor.c
+++ linux/drivers/mtd/spi-nor/spi-nor.c
@@ -246,55 +246,45 @@ struct flash_info {
 #define JEDEC_MFR(info)	((info)->id[0])
 
 /**
- * spi_nor_spimem_xfer_data() - helper function to read/write data to
- *                              flash's memory region
+ * spi_nor_spimem_bounce() - check if a bounce buffer is needed for the data
+ *                           transfer
  * @nor:        pointer to 'struct spi_nor'
  * @op:         pointer to 'struct spi_mem_op' template for transfer
  *
- * Return: number of bytes transferred on success, -errno otherwise
+ * If we have to use the bounce buffer, the data field in @op will be updated.
+ *
+ * Return: true if the bounce buffer is needed, false if not
  */
-static ssize_t spi_nor_spimem_xfer_data(struct spi_nor *nor,
-					struct spi_mem_op *op)
+static bool spi_nor_spimem_bounce(struct spi_nor *nor, struct spi_mem_op *op)
 {
-	bool usebouncebuf = false;
-	void *rdbuf = NULL;
-	const void *buf;
-	int ret;
-
-	if (op->data.dir == SPI_MEM_DATA_IN)
-		buf = op->data.buf.in;
-	else
-		buf = op->data.buf.out;
-
-	if (object_is_on_stack(buf) || !virt_addr_valid(buf))
-		usebouncebuf = true;
-
-	if (usebouncebuf) {
+	/* op->data.buf.in occupies the same memory as op->data.buf.out */
+	if (object_is_on_stack(op->data.buf.in) ||
+	    !virt_addr_valid(op->data.buf.in)) {
 		if (op->data.nbytes > nor->bouncebuf_size)
 			op->data.nbytes = nor->bouncebuf_size;
-
-		if (op->data.dir == SPI_MEM_DATA_IN) {
-			rdbuf = op->data.buf.in;
-			op->data.buf.in = nor->bouncebuf;
-		} else {
-			op->data.buf.out = nor->bouncebuf;
-			memcpy(nor->bouncebuf, buf,
-			       op->data.nbytes);
-		}
+		op->data.buf.in = nor->bouncebuf;
+		return true;
 	}
 
-	ret = spi_mem_adjust_op_size(nor->spimem, op);
-	if (ret)
-		return ret;
-
-	ret = spi_mem_exec_op(nor->spimem, op);
-	if (ret)
-		return ret;
+	return false;
+}
+
+/**
+ * spi_nor_spimem_exec_op() - execute a memory operation
+ * @nor:        pointer to 'struct spi_nor'
+ * @op:         pointer to 'struct spi_mem_op' template for transfer
+ *
+ * Return: 0 on success, -error otherwise.
+ */
+static int spi_nor_spimem_exec_op(struct spi_nor *nor, struct spi_mem_op *op)
+{
+	int error;
 
-	if (usebouncebuf && op->data.dir == SPI_MEM_DATA_IN)
-		memcpy(rdbuf, nor->bouncebuf, op->data.nbytes);
+	error = spi_mem_adjust_op_size(nor->spimem, op);
+	if (error)
+		return error;
 
-	return op->data.nbytes;
+	return spi_mem_exec_op(nor->spimem, op);
 }
 
 /**
@@ -315,6 +305,8 @@ static ssize_t spi_nor_spimem_read_data(
 			   SPI_MEM_OP_ADDR(nor->addr_width, from, 1),
 			   SPI_MEM_OP_DUMMY(nor->read_dummy, 1),
 			   SPI_MEM_OP_DATA_IN(len, buf, 1));
+	bool usebouncebuf;
+	int error;
 
 	/* get transfer protocols. */
 	op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->read_proto);
@@ -325,7 +317,16 @@ static ssize_t spi_nor_spimem_read_data(
 	/* convert the dummy cycles to the number of bytes */
 	op.dummy.nbytes = (nor->read_dummy * op.dummy.buswidth) / 8;
 
-	return spi_nor_spimem_xfer_data(nor, &op);
+	usebouncebuf = spi_nor_spimem_bounce(nor, &op);
+
+	error = spi_nor_spimem_exec_op(nor, &op);
+	if (error)
+		return error;
+
+	if (usebouncebuf)
+		memcpy(buf, op.data.buf.in, op.data.nbytes);
+
+	return op.data.nbytes;
 }
 
 /**
@@ -364,6 +365,8 @@ static ssize_t spi_nor_spimem_write_data
 			   SPI_MEM_OP_ADDR(nor->addr_width, to, 1),
 			   SPI_MEM_OP_NO_DUMMY,
 			   SPI_MEM_OP_DATA_OUT(len, buf, 1));
+	bool usebouncebuf;
+	int error;
 
 	op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->write_proto);
 	op.addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->write_proto);
@@ -372,7 +375,15 @@ static ssize_t spi_nor_spimem_write_data
 	if (nor->program_opcode == SPINOR_OP_AAI_WP && nor->sst_write_second)
 		op.addr.nbytes = 0;
 
-	return spi_nor_spimem_xfer_data(nor, &op);
+	usebouncebuf = spi_nor_spimem_bounce(nor, &op);
+	if (usebouncebuf)
+		memcpy(nor->bouncebuf, buf, op.data.nbytes);
+
+	error = spi_nor_spimem_exec_op(nor, &op);
+	if (error)
+		return error;
+
+	return op.data.nbytes;
 }
 
 /**

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^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH v4 2/2] mtd: spi-nor: use spi-mem dirmap API
  2020-01-27 20:23 [PATCH v4 0/2] mtd: spi-nor: use spi-mem dirmap API Sergei Shtylyov
  2020-01-27 20:28 ` [PATCH v4 1/2] mtd: spi-nor: split spi_nor_spimem_xfer_data() Sergei Shtylyov
@ 2020-01-27 20:29 ` Sergei Shtylyov
  2020-02-16 23:03   ` Tudor.Ambarus
  1 sibling, 1 reply; 8+ messages in thread
From: Sergei Shtylyov @ 2020-01-27 20:29 UTC (permalink / raw)
  To: Tudor Ambarus, Miquel Raynal, Richard Weinberger,
	Vignesh Raghavendra, linux-mtd

Make use of the spi-mem direct mapping API to let advanced controllers
optimize read/write operations when they support direct mapping.

Based on the original patch by Boris Brezillon
<boris.brezillon@bootlin.com>.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

---
Changes in version 4:
- moved the spi_mem_dirmap_{read|write}() calls closer to the ending of
  spi_nor_{read|write}(), adapting to the chnages caused by the new patch
  splitting spi_nor_spimem_xfer_data()...

Changes in version 3:
- simplified the way spi_mem_dirmap_{read|write}() are called;
- added Boris' tag.

Changes in version 2:
- moved the spi_mem_dirmap_{read|write}() calls from spi_nor_{read|write}() to
  spi_nor_spimem_{read|write}_data().

 drivers/mtd/spi-nor/spi-nor.c |   97 ++++++++++++++++++++++++++++++++++++++----
 include/linux/mtd/spi-nor.h   |    5 ++
 2 files changed, 93 insertions(+), 9 deletions(-)

Index: linux/drivers/mtd/spi-nor/spi-nor.c
===================================================================
--- linux.orig/drivers/mtd/spi-nor/spi-nor.c
+++ linux/drivers/mtd/spi-nor/spi-nor.c
@@ -306,6 +306,7 @@ static ssize_t spi_nor_spimem_read_data(
 			   SPI_MEM_OP_DUMMY(nor->read_dummy, 1),
 			   SPI_MEM_OP_DATA_IN(len, buf, 1));
 	bool usebouncebuf;
+	ssize_t nbytes;
 	int error;
 
 	/* get transfer protocols. */
@@ -319,14 +320,23 @@ static ssize_t spi_nor_spimem_read_data(
 
 	usebouncebuf = spi_nor_spimem_bounce(nor, &op);
 
-	error = spi_nor_spimem_exec_op(nor, &op);
-	if (error)
-		return error;
+	if (nor->dirmap.rdesc) {
+		nbytes = spi_mem_dirmap_read(nor->dirmap.rdesc, op.addr.val,
+					     op.data.nbytes, op.data.buf.in);
+		if (nbytes < 0)
+			return nbytes;
+	} else {
+		error = spi_nor_spimem_exec_op(nor, &op);
+		if (error)
+			return error;
+
+		nbytes = op.data.nbytes;
+	}
 
 	if (usebouncebuf)
-		memcpy(buf, op.data.buf.in, op.data.nbytes);
+		memcpy(buf, op.data.buf.in, nbytes);
 
-	return op.data.nbytes;
+	return nbytes;
 }
 
 /**
@@ -366,6 +376,7 @@ static ssize_t spi_nor_spimem_write_data
 			   SPI_MEM_OP_NO_DUMMY,
 			   SPI_MEM_OP_DATA_OUT(len, buf, 1));
 	bool usebouncebuf;
+	ssize_t nbytes;
 	int error;
 
 	op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->write_proto);
@@ -379,11 +390,19 @@ static ssize_t spi_nor_spimem_write_data
 	if (usebouncebuf)
 		memcpy(nor->bouncebuf, buf, op.data.nbytes);
 
-	error = spi_nor_spimem_exec_op(nor, &op);
-	if (error)
-		return error;
+	if (nor->dirmap.wdesc) {
+		nbytes = spi_mem_dirmap_write(nor->dirmap.wdesc, op.addr.val,
+					   op.data.nbytes, op.data.buf.out);
+		if (nbytes < 0)
+			return nbytes;
+	} else {
+		error = spi_nor_spimem_exec_op(nor, &op);
+		if (error)
+			return error;
+		nbytes = op.data.nbytes;
+	}
 
-	return op.data.nbytes;
+	return nbytes;
 }
 
 /**
@@ -5270,6 +5289,58 @@ int spi_nor_scan(struct spi_nor *nor, co
 }
 EXPORT_SYMBOL_GPL(spi_nor_scan);
 
+static int spi_nor_create_read_dirmap(struct spi_nor *nor)
+{
+	struct spi_mem_dirmap_info info = {
+		.op_tmpl = SPI_MEM_OP(SPI_MEM_OP_CMD(nor->read_opcode, 1),
+				      SPI_MEM_OP_ADDR(nor->addr_width, 0, 1),
+				      SPI_MEM_OP_DUMMY(nor->read_dummy, 1),
+				      SPI_MEM_OP_DATA_IN(0, NULL, 1)),
+		.offset = 0,
+		.length = nor->mtd.size,
+	};
+	struct spi_mem_op *op = &info.op_tmpl;
+
+	/* get transfer protocols. */
+	op->cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->read_proto);
+	op->addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->read_proto);
+	op->dummy.buswidth = op->addr.buswidth;
+	op->data.buswidth = spi_nor_get_protocol_data_nbits(nor->read_proto);
+
+	/* convert the dummy cycles to the number of bytes */
+	op->dummy.nbytes = (nor->read_dummy * op->dummy.buswidth) / 8;
+
+	nor->dirmap.rdesc = devm_spi_mem_dirmap_create(nor->dev, nor->spimem,
+						       &info);
+	return PTR_ERR_OR_ZERO(nor->dirmap.rdesc);
+}
+
+static int spi_nor_create_write_dirmap(struct spi_nor *nor)
+{
+	struct spi_mem_dirmap_info info = {
+		.op_tmpl = SPI_MEM_OP(SPI_MEM_OP_CMD(nor->program_opcode, 1),
+				      SPI_MEM_OP_ADDR(nor->addr_width, 0, 1),
+				      SPI_MEM_OP_NO_DUMMY,
+				      SPI_MEM_OP_DATA_OUT(0, NULL, 1)),
+		.offset = 0,
+		.length = nor->mtd.size,
+	};
+	struct spi_mem_op *op = &info.op_tmpl;
+
+	/* get transfer protocols. */
+	op->cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->write_proto);
+	op->addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->write_proto);
+	op->dummy.buswidth = op->addr.buswidth;
+	op->data.buswidth = spi_nor_get_protocol_data_nbits(nor->write_proto);
+
+	if (nor->program_opcode == SPINOR_OP_AAI_WP && nor->sst_write_second)
+		op->addr.nbytes = 0;
+
+	nor->dirmap.wdesc = devm_spi_mem_dirmap_create(nor->dev, nor->spimem,
+						       &info);
+	return PTR_ERR_OR_ZERO(nor->dirmap.wdesc);
+}
+
 static int spi_nor_probe(struct spi_mem *spimem)
 {
 	struct spi_device *spi = spimem->spi;
@@ -5331,6 +5402,14 @@ static int spi_nor_probe(struct spi_mem
 			return -ENOMEM;
 	}
 
+	ret = spi_nor_create_read_dirmap(nor);
+	if (ret)
+		return ret;
+
+	ret = spi_nor_create_write_dirmap(nor);
+	if (ret)
+		return ret;
+
 	return mtd_device_register(&nor->mtd, data ? data->parts : NULL,
 				   data ? data->nr_parts : 0);
 }
Index: linux/include/linux/mtd/spi-nor.h
===================================================================
--- linux.orig/include/linux/mtd/spi-nor.h
+++ linux/include/linux/mtd/spi-nor.h
@@ -604,6 +604,11 @@ struct spi_nor {
 
 	struct spi_nor_flash_parameter params;
 
+	struct {
+		struct spi_mem_dirmap_desc *rdesc;
+		struct spi_mem_dirmap_desc *wdesc;
+	} dirmap;
+
 	void *priv;
 };
 

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^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v4 1/2] mtd: spi-nor: split spi_nor_spimem_xfer_data()
  2020-01-27 20:28 ` [PATCH v4 1/2] mtd: spi-nor: split spi_nor_spimem_xfer_data() Sergei Shtylyov
@ 2020-01-28  6:50   ` Boris Brezillon
  2020-02-16 22:40   ` Tudor.Ambarus
  1 sibling, 0 replies; 8+ messages in thread
From: Boris Brezillon @ 2020-01-28  6:50 UTC (permalink / raw)
  To: Sergei Shtylyov
  Cc: Richard Weinberger, Miquel Raynal, linux-mtd,
	Vignesh Raghavendra, Tudor Ambarus

On Mon, 27 Jan 2020 23:28:05 +0300
Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> wrote:

> spi_nor_spimem_xfer_data() being a helper function for the data reads/
> writes contains 3 fragments that depend on the data direction; and I'm
> going to add another one to call the SPI dirmap API...
> I think this function should be split so that the common fragments are
> put into 2 functions, spi_nor_spimem_bounce() and spi_nor_spimem_exec_op()
> called from spi_nor_spimem_{read|write}_data(), and the data direction
> dependent bits moved back into those read/write functions -- that way we
> would be able to avoid *goto*s otherwise needed in the next patch adding
> the  SPI dirmap support...
> 
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

> 
> ---
> Changes in version 4:
> - new patch.
> 
>  drivers/mtd/spi-nor/spi-nor.c |   91 +++++++++++++++++++++++-------------------
>  1 file changed, 51 insertions(+), 40 deletions(-)
> 
> Index: linux/drivers/mtd/spi-nor/spi-nor.c
> ===================================================================
> --- linux.orig/drivers/mtd/spi-nor/spi-nor.c
> +++ linux/drivers/mtd/spi-nor/spi-nor.c
> @@ -246,55 +246,45 @@ struct flash_info {
>  #define JEDEC_MFR(info)	((info)->id[0])
>  
>  /**
> - * spi_nor_spimem_xfer_data() - helper function to read/write data to
> - *                              flash's memory region
> + * spi_nor_spimem_bounce() - check if a bounce buffer is needed for the data
> + *                           transfer
>   * @nor:        pointer to 'struct spi_nor'
>   * @op:         pointer to 'struct spi_mem_op' template for transfer
>   *
> - * Return: number of bytes transferred on success, -errno otherwise
> + * If we have to use the bounce buffer, the data field in @op will be updated.
> + *
> + * Return: true if the bounce buffer is needed, false if not
>   */
> -static ssize_t spi_nor_spimem_xfer_data(struct spi_nor *nor,
> -					struct spi_mem_op *op)
> +static bool spi_nor_spimem_bounce(struct spi_nor *nor, struct spi_mem_op *op)
>  {
> -	bool usebouncebuf = false;
> -	void *rdbuf = NULL;
> -	const void *buf;
> -	int ret;
> -
> -	if (op->data.dir == SPI_MEM_DATA_IN)
> -		buf = op->data.buf.in;
> -	else
> -		buf = op->data.buf.out;
> -
> -	if (object_is_on_stack(buf) || !virt_addr_valid(buf))
> -		usebouncebuf = true;
> -
> -	if (usebouncebuf) {
> +	/* op->data.buf.in occupies the same memory as op->data.buf.out */
> +	if (object_is_on_stack(op->data.buf.in) ||
> +	    !virt_addr_valid(op->data.buf.in)) {
>  		if (op->data.nbytes > nor->bouncebuf_size)
>  			op->data.nbytes = nor->bouncebuf_size;
> -
> -		if (op->data.dir == SPI_MEM_DATA_IN) {
> -			rdbuf = op->data.buf.in;
> -			op->data.buf.in = nor->bouncebuf;
> -		} else {
> -			op->data.buf.out = nor->bouncebuf;
> -			memcpy(nor->bouncebuf, buf,
> -			       op->data.nbytes);
> -		}
> +		op->data.buf.in = nor->bouncebuf;
> +		return true;
>  	}
>  
> -	ret = spi_mem_adjust_op_size(nor->spimem, op);
> -	if (ret)
> -		return ret;
> -
> -	ret = spi_mem_exec_op(nor->spimem, op);
> -	if (ret)
> -		return ret;
> +	return false;
> +}
> +
> +/**
> + * spi_nor_spimem_exec_op() - execute a memory operation
> + * @nor:        pointer to 'struct spi_nor'
> + * @op:         pointer to 'struct spi_mem_op' template for transfer
> + *
> + * Return: 0 on success, -error otherwise.
> + */
> +static int spi_nor_spimem_exec_op(struct spi_nor *nor, struct spi_mem_op *op)
> +{
> +	int error;
>  
> -	if (usebouncebuf && op->data.dir == SPI_MEM_DATA_IN)
> -		memcpy(rdbuf, nor->bouncebuf, op->data.nbytes);
> +	error = spi_mem_adjust_op_size(nor->spimem, op);
> +	if (error)
> +		return error;
>  
> -	return op->data.nbytes;
> +	return spi_mem_exec_op(nor->spimem, op);
>  }
>  
>  /**
> @@ -315,6 +305,8 @@ static ssize_t spi_nor_spimem_read_data(
>  			   SPI_MEM_OP_ADDR(nor->addr_width, from, 1),
>  			   SPI_MEM_OP_DUMMY(nor->read_dummy, 1),
>  			   SPI_MEM_OP_DATA_IN(len, buf, 1));
> +	bool usebouncebuf;
> +	int error;
>  
>  	/* get transfer protocols. */
>  	op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->read_proto);
> @@ -325,7 +317,16 @@ static ssize_t spi_nor_spimem_read_data(
>  	/* convert the dummy cycles to the number of bytes */
>  	op.dummy.nbytes = (nor->read_dummy * op.dummy.buswidth) / 8;
>  
> -	return spi_nor_spimem_xfer_data(nor, &op);
> +	usebouncebuf = spi_nor_spimem_bounce(nor, &op);
> +
> +	error = spi_nor_spimem_exec_op(nor, &op);
> +	if (error)
> +		return error;
> +
> +	if (usebouncebuf)
> +		memcpy(buf, op.data.buf.in, op.data.nbytes);
> +
> +	return op.data.nbytes;
>  }
>  
>  /**
> @@ -364,6 +365,8 @@ static ssize_t spi_nor_spimem_write_data
>  			   SPI_MEM_OP_ADDR(nor->addr_width, to, 1),
>  			   SPI_MEM_OP_NO_DUMMY,
>  			   SPI_MEM_OP_DATA_OUT(len, buf, 1));
> +	bool usebouncebuf;
> +	int error;
>  
>  	op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->write_proto);
>  	op.addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->write_proto);
> @@ -372,7 +375,15 @@ static ssize_t spi_nor_spimem_write_data
>  	if (nor->program_opcode == SPINOR_OP_AAI_WP && nor->sst_write_second)
>  		op.addr.nbytes = 0;
>  
> -	return spi_nor_spimem_xfer_data(nor, &op);
> +	usebouncebuf = spi_nor_spimem_bounce(nor, &op);
> +	if (usebouncebuf)
> +		memcpy(nor->bouncebuf, buf, op.data.nbytes);
> +
> +	error = spi_nor_spimem_exec_op(nor, &op);
> +	if (error)
> +		return error;
> +
> +	return op.data.nbytes;
>  }
>  
>  /**
> 
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/


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

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v4 1/2] mtd: spi-nor: split spi_nor_spimem_xfer_data()
  2020-01-27 20:28 ` [PATCH v4 1/2] mtd: spi-nor: split spi_nor_spimem_xfer_data() Sergei Shtylyov
  2020-01-28  6:50   ` Boris Brezillon
@ 2020-02-16 22:40   ` Tudor.Ambarus
  2020-02-17 17:47     ` Sergei Shtylyov
  1 sibling, 1 reply; 8+ messages in thread
From: Tudor.Ambarus @ 2020-02-16 22:40 UTC (permalink / raw)
  To: sergei.shtylyov; +Cc: richard, linux-mtd, vigneshr, miquel.raynal

Hi, Sergei,

Looks good. Just a nit below that I can fix it when applying. Let me know if 
you're ok with the change.

On Monday, January 27, 2020 10:28:05 PM EET Sergei Shtylyov wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the
> content is safe
> 
> spi_nor_spimem_xfer_data() being a helper function for the data reads/
> writes contains 3 fragments that depend on the data direction; and I'm
> going to add another one to call the SPI dirmap API...
> I think this function should be split so that the common fragments are
> put into 2 functions, spi_nor_spimem_bounce() and spi_nor_spimem_exec_op()
> called from spi_nor_spimem_{read|write}_data(), and the data direction
> dependent bits moved back into those read/write functions -- that way we
> would be able to avoid *goto*s otherwise needed in the next patch adding
> the  SPI dirmap support...
> 
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> 
> ---
> Changes in version 4:
> - new patch.
> 
>  drivers/mtd/spi-nor/spi-nor.c |   91
> +++++++++++++++++++++++------------------- 1 file changed, 51
> insertions(+), 40 deletions(-)
> 
> Index: linux/drivers/mtd/spi-nor/spi-nor.c
> ===================================================================
> --- linux.orig/drivers/mtd/spi-nor/spi-nor.c
> +++ linux/drivers/mtd/spi-nor/spi-nor.c
> @@ -246,55 +246,45 @@ struct flash_info {
>  #define JEDEC_MFR(info)        ((info)->id[0])
> 
>  /**
> - * spi_nor_spimem_xfer_data() - helper function to read/write data to
> - *                              flash's memory region
> + * spi_nor_spimem_bounce() - check if a bounce buffer is needed for the
> data + *                           transfer
>   * @nor:        pointer to 'struct spi_nor'
>   * @op:         pointer to 'struct spi_mem_op' template for transfer
>   *
> - * Return: number of bytes transferred on success, -errno otherwise
> + * If we have to use the bounce buffer, the data field in @op will be
> updated. + *
> + * Return: true if the bounce buffer is needed, false if not
>   */
> -static ssize_t spi_nor_spimem_xfer_data(struct spi_nor *nor,
> -                                       struct spi_mem_op *op)
> +static bool spi_nor_spimem_bounce(struct spi_nor *nor, struct spi_mem_op
> *op) {
> -       bool usebouncebuf = false;
> -       void *rdbuf = NULL;
> -       const void *buf;
> -       int ret;
> -
> -       if (op->data.dir == SPI_MEM_DATA_IN)
> -               buf = op->data.buf.in;
> -       else
> -               buf = op->data.buf.out;
> -
> -       if (object_is_on_stack(buf) || !virt_addr_valid(buf))
> -               usebouncebuf = true;
> -
> -       if (usebouncebuf) {
> +       /* op->data.buf.in occupies the same memory as op->data.buf.out */
> +       if (object_is_on_stack(op->data.buf.in) ||
> +           !virt_addr_valid(op->data.buf.in)) {
>                 if (op->data.nbytes > nor->bouncebuf_size)
>                         op->data.nbytes = nor->bouncebuf_size;
> -
> -               if (op->data.dir == SPI_MEM_DATA_IN) {
> -                       rdbuf = op->data.buf.in;
> -                       op->data.buf.in = nor->bouncebuf;
> -               } else {
> -                       op->data.buf.out = nor->bouncebuf;
> -                       memcpy(nor->bouncebuf, buf,
> -                              op->data.nbytes);
> -               }
> +               op->data.buf.in = nor->bouncebuf;
> +               return true;
>         }
> 
> -       ret = spi_mem_adjust_op_size(nor->spimem, op);
> -       if (ret)
> -               return ret;
> -
> -       ret = spi_mem_exec_op(nor->spimem, op);
> -       if (ret)
> -               return ret;
> +       return false;
> +}
> +
> +/**
> + * spi_nor_spimem_exec_op() - execute a memory operation
> + * @nor:        pointer to 'struct spi_nor'
> + * @op:         pointer to 'struct spi_mem_op' template for transfer
> + *
> + * Return: 0 on success, -error otherwise.
> + */
> +static int spi_nor_spimem_exec_op(struct spi_nor *nor, struct spi_mem_op
> *op) +{
> +       int error;
> 
> -       if (usebouncebuf && op->data.dir == SPI_MEM_DATA_IN)
> -               memcpy(rdbuf, nor->bouncebuf, op->data.nbytes);
> +       error = spi_mem_adjust_op_size(nor->spimem, op);
> +       if (error)
> +               return error;
> 
> -       return op->data.nbytes;
> +       return spi_mem_exec_op(nor->spimem, op);
>  }
> 
>  /**
> @@ -315,6 +305,8 @@ static ssize_t spi_nor_spimem_read_data(
>                            SPI_MEM_OP_ADDR(nor->addr_width, from, 1),
>                            SPI_MEM_OP_DUMMY(nor->read_dummy, 1),
>                            SPI_MEM_OP_DATA_IN(len, buf, 1));
> +       bool usebouncebuf;
> +       int error;
> 
>         /* get transfer protocols. */
>         op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->read_proto);
> @@ -325,7 +317,16 @@ static ssize_t spi_nor_spimem_read_data(
>         /* convert the dummy cycles to the number of bytes */
>         op.dummy.nbytes = (nor->read_dummy * op.dummy.buswidth) / 8;
> 
> -       return spi_nor_spimem_xfer_data(nor, &op);
> +       usebouncebuf = spi_nor_spimem_bounce(nor, &op);
> +
> +       error = spi_nor_spimem_exec_op(nor, &op);
> +       if (error)
> +               return error;
> +
> +       if (usebouncebuf)
> +               memcpy(buf, op.data.buf.in, op.data.nbytes);
> +
> +       return op.data.nbytes;
>  }
> 
>  /**
> @@ -364,6 +365,8 @@ static ssize_t spi_nor_spimem_write_data
>                            SPI_MEM_OP_ADDR(nor->addr_width, to, 1),
>                            SPI_MEM_OP_NO_DUMMY,
>                            SPI_MEM_OP_DATA_OUT(len, buf, 1));
> +       bool usebouncebuf;
> +       int error;
> 
>         op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->write_proto);
> op.addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->write_proto); @@
> -372,7 +375,15 @@ static ssize_t spi_nor_spimem_write_data
>         if (nor->program_opcode == SPINOR_OP_AAI_WP &&
> nor->sst_write_second) op.addr.nbytes = 0;
> 
> -       return spi_nor_spimem_xfer_data(nor, &op);
> +       usebouncebuf = spi_nor_spimem_bounce(nor, &op);
> +       if (usebouncebuf)
> +               memcpy(nor->bouncebuf, buf, op.data.nbytes);

How about memcpy(nor->bouncebuf, buf, len); instead?

spi_nor_spimem_bounce() does not modify op.data.nbytes. Using len is more 
straight forward than op.data.bytes because the reader doesn't have to verify 
if length was updated in spi_nor_spimem_bounce() or not.

Cheers,
ta




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

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v4 2/2] mtd: spi-nor: use spi-mem dirmap API
  2020-01-27 20:29 ` [PATCH v4 2/2] mtd: spi-nor: use spi-mem dirmap API Sergei Shtylyov
@ 2020-02-16 23:03   ` Tudor.Ambarus
  2020-02-17 18:43     ` Sergei Shtylyov
  0 siblings, 1 reply; 8+ messages in thread
From: Tudor.Ambarus @ 2020-02-16 23:03 UTC (permalink / raw)
  To: sergei.shtylyov; +Cc: richard, linux-mtd, vigneshr, miquel.raynal

Hi, Sergei,

Looks good. Few nits below that I can fix when applying. Let me know if 
you're ok with the changes.

On Monday, January 27, 2020 10:29:06 PM EET Sergei Shtylyov wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the
> content is safe
> 
> Make use of the spi-mem direct mapping API to let advanced controllers
> optimize read/write operations when they support direct mapping.
> 
> Based on the original patch by Boris Brezillon
> <boris.brezillon@bootlin.com>.
> 
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
> 
> ---
> Changes in version 4:
> - moved the spi_mem_dirmap_{read|write}() calls closer to the ending of
>   spi_nor_{read|write}(), adapting to the chnages caused by the new patch
>   splitting spi_nor_spimem_xfer_data()...
> 
> Changes in version 3:
> - simplified the way spi_mem_dirmap_{read|write}() are called;
> - added Boris' tag.
> 
> Changes in version 2:
> - moved the spi_mem_dirmap_{read|write}() calls from spi_nor_{read|write}()
> to spi_nor_spimem_{read|write}_data().
> 
>  drivers/mtd/spi-nor/spi-nor.c |   97
> ++++++++++++++++++++++++++++++++++++++---- include/linux/mtd/spi-nor.h   | 
>   5 ++
>  2 files changed, 93 insertions(+), 9 deletions(-)
> 
> Index: linux/drivers/mtd/spi-nor/spi-nor.c
> ===================================================================
> --- linux.orig/drivers/mtd/spi-nor/spi-nor.c
> +++ linux/drivers/mtd/spi-nor/spi-nor.c
> @@ -306,6 +306,7 @@ static ssize_t spi_nor_spimem_read_data(
>                            SPI_MEM_OP_DUMMY(nor->read_dummy, 1),
>                            SPI_MEM_OP_DATA_IN(len, buf, 1));
>         bool usebouncebuf;
> +       ssize_t nbytes;
>         int error;
> 
>         /* get transfer protocols. */
> @@ -319,14 +320,23 @@ static ssize_t spi_nor_spimem_read_data(
> 
>         usebouncebuf = spi_nor_spimem_bounce(nor, &op);
> 
> -       error = spi_nor_spimem_exec_op(nor, &op);
> -       if (error)
> -               return error;
> +       if (nor->dirmap.rdesc) {
> +               nbytes = spi_mem_dirmap_read(nor->dirmap.rdesc, op.addr.val,

op.data.nbytes = spi_mem_dirmap_read() ?

This way we can get rid of the local variable nbytes.

> +                                            op.data.nbytes,
> op.data.buf.in); +               if (nbytes < 0)
> +                       return nbytes;
> +       } else {
> +               error = spi_nor_spimem_exec_op(nor, &op);
> +               if (error)
> +                       return error;
> +
> +               nbytes = op.data.nbytes;
> +       }
> 
>         if (usebouncebuf)
> -               memcpy(buf, op.data.buf.in, op.data.nbytes);
> +               memcpy(buf, op.data.buf.in, nbytes);
> 
> -       return op.data.nbytes;
> +       return nbytes;
>  }
> 
>  /**
> @@ -366,6 +376,7 @@ static ssize_t spi_nor_spimem_write_data
>                            SPI_MEM_OP_NO_DUMMY,
>                            SPI_MEM_OP_DATA_OUT(len, buf, 1));
>         bool usebouncebuf;
> +       ssize_t nbytes;
>         int error;
> 
>         op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->write_proto);
> @@ -379,11 +390,19 @@ static ssize_t spi_nor_spimem_write_data
>         if (usebouncebuf)
>                 memcpy(nor->bouncebuf, buf, op.data.nbytes);
> 
> -       error = spi_nor_spimem_exec_op(nor, &op);
> -       if (error)
> -               return error;
> +       if (nor->dirmap.wdesc) {
> +               nbytes = spi_mem_dirmap_write(nor->dirmap.wdesc,
> op.addr.val, +                                          op.data.nbytes,

I'll align this to "("

op.data.nbytes = spi_mem_dirmap_write() ?

This way we can get rid of the local variable nbytes.

> op.data.buf.out); +               if (nbytes < 0)
> +                       return nbytes;

you already return nbytes below, we can drop this check.

> +       } else {
> +               error = spi_nor_spimem_exec_op(nor, &op);
> +               if (error)
> +                       return error;
> +               nbytes = op.data.nbytes;
> +       }
> 
> -       return op.data.nbytes;
> +       return nbytes;
>  }

Cheers,
ta


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

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v4 1/2] mtd: spi-nor: split spi_nor_spimem_xfer_data()
  2020-02-16 22:40   ` Tudor.Ambarus
@ 2020-02-17 17:47     ` Sergei Shtylyov
  0 siblings, 0 replies; 8+ messages in thread
From: Sergei Shtylyov @ 2020-02-17 17:47 UTC (permalink / raw)
  To: Tudor.Ambarus; +Cc: richard, linux-mtd, vigneshr, miquel.raynal

On 02/17/2020 01:40 AM, Tudor.Ambarus@microchip.com wrote:

> Looks good. Just a nit below that I can fix it when applying. Let me know if 
> you're ok with the change.
> 
> On Monday, January 27, 2020 10:28:05 PM EET Sergei Shtylyov wrote:
>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the
>> content is safe
>>
>> spi_nor_spimem_xfer_data() being a helper function for the data reads/
>> writes contains 3 fragments that depend on the data direction; and I'm
>> going to add another one to call the SPI dirmap API...
>> I think this function should be split so that the common fragments are
>> put into 2 functions, spi_nor_spimem_bounce() and spi_nor_spimem_exec_op()
>> called from spi_nor_spimem_{read|write}_data(), and the data direction
>> dependent bits moved back into those read/write functions -- that way we
>> would be able to avoid *goto*s otherwise needed in the next patch adding
>> the  SPI dirmap support...
>>
>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>>
>> ---
>> Changes in version 4:
>> - new patch.
>>
>>  drivers/mtd/spi-nor/spi-nor.c |   91
>> +++++++++++++++++++++++------------------- 1 file changed, 51
>> insertions(+), 40 deletions(-)
>>
>> Index: linux/drivers/mtd/spi-nor/spi-nor.c
>> ===================================================================
>> --- linux.orig/drivers/mtd/spi-nor/spi-nor.c
>> +++ linux/drivers/mtd/spi-nor/spi-nor.c
>> @@ -246,55 +246,45 @@ struct flash_info {
>>  #define JEDEC_MFR(info)        ((info)->id[0])
>>
>>  /**
>> - * spi_nor_spimem_xfer_data() - helper function to read/write data to
>> - *                              flash's memory region
>> + * spi_nor_spimem_bounce() - check if a bounce buffer is needed for the
>> data + *                           transfer
>>   * @nor:        pointer to 'struct spi_nor'
>>   * @op:         pointer to 'struct spi_mem_op' template for transfer
>>   *
>> - * Return: number of bytes transferred on success, -errno otherwise
>> + * If we have to use the bounce buffer, the data field in @op will be
>> updated. + *
>> + * Return: true if the bounce buffer is needed, false if not
>>   */
>> -static ssize_t spi_nor_spimem_xfer_data(struct spi_nor *nor,
>> -                                       struct spi_mem_op *op)
>> +static bool spi_nor_spimem_bounce(struct spi_nor *nor, struct spi_mem_op
>> *op) {
>> -       bool usebouncebuf = false;
>> -       void *rdbuf = NULL;
>> -       const void *buf;
>> -       int ret;
>> -
>> -       if (op->data.dir == SPI_MEM_DATA_IN)
>> -               buf = op->data.buf.in;
>> -       else
>> -               buf = op->data.buf.out;
>> -
>> -       if (object_is_on_stack(buf) || !virt_addr_valid(buf))
>> -               usebouncebuf = true;
>> -
>> -       if (usebouncebuf) {
>> +       /* op->data.buf.in occupies the same memory as op->data.buf.out */
>> +       if (object_is_on_stack(op->data.buf.in) ||
>> +           !virt_addr_valid(op->data.buf.in)) {
>>                 if (op->data.nbytes > nor->bouncebuf_size)
>>                         op->data.nbytes = nor->bouncebuf_size;
>> -
>> -               if (op->data.dir == SPI_MEM_DATA_IN) {
>> -                       rdbuf = op->data.buf.in;
>> -                       op->data.buf.in = nor->bouncebuf;
>> -               } else {
>> -                       op->data.buf.out = nor->bouncebuf;
>> -                       memcpy(nor->bouncebuf, buf,
>> -                              op->data.nbytes);
>> -               }
>> +               op->data.buf.in = nor->bouncebuf;
>> +               return true;
>>         }
>>
>> -       ret = spi_mem_adjust_op_size(nor->spimem, op);
>> -       if (ret)
>> -               return ret;
>> -
>> -       ret = spi_mem_exec_op(nor->spimem, op);
>> -       if (ret)
>> -               return ret;
>> +       return false;
>> +}
>> +
>> +/**
>> + * spi_nor_spimem_exec_op() - execute a memory operation
>> + * @nor:        pointer to 'struct spi_nor'
>> + * @op:         pointer to 'struct spi_mem_op' template for transfer
>> + *
>> + * Return: 0 on success, -error otherwise.
>> + */
>> +static int spi_nor_spimem_exec_op(struct spi_nor *nor, struct spi_mem_op
>> *op) +{
>> +       int error;
>>
>> -       if (usebouncebuf && op->data.dir == SPI_MEM_DATA_IN)
>> -               memcpy(rdbuf, nor->bouncebuf, op->data.nbytes);
>> +       error = spi_mem_adjust_op_size(nor->spimem, op);
>> +       if (error)
>> +               return error;
>>
>> -       return op->data.nbytes;
>> +       return spi_mem_exec_op(nor->spimem, op);
>>  }
>>
>>  /**
[...]
>> @@ -364,6 +365,8 @@ static ssize_t spi_nor_spimem_write_data
>>                            SPI_MEM_OP_ADDR(nor->addr_width, to, 1),
>>                            SPI_MEM_OP_NO_DUMMY,
>>                            SPI_MEM_OP_DATA_OUT(len, buf, 1));
>> +       bool usebouncebuf;
>> +       int error;
>>
>>         op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->write_proto);
>> op.addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->write_proto); @@
>> -372,7 +375,15 @@ static ssize_t spi_nor_spimem_write_data
>>         if (nor->program_opcode == SPINOR_OP_AAI_WP &&
>> nor->sst_write_second) op.addr.nbytes = 0;
>>
>> -       return spi_nor_spimem_xfer_data(nor, &op);
>> +       usebouncebuf = spi_nor_spimem_bounce(nor, &op);
>> +       if (usebouncebuf)
>> +               memcpy(nor->bouncebuf, buf, op.data.nbytes);
> 
> How about memcpy(nor->bouncebuf, buf, len); instead?

   spi_nor_spimem_bounce() changes op.data.nbytes iff the original buffer is
larger than the bounce buffer. I don't want to copy the data which I'm unable
to write put anyway.

> spi_nor_spimem_bounce() does not modify op.data.nbytes.

   Surely it does!

> Using len is more 
> straight forward than op.data.bytes because the reader doesn't have to verify 
> if length was updated in spi_nor_spimem_bounce() or not.

   Sorry, I can't agree with your analysis...

> Cheers,
> ta

MBR, Sergei

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

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v4 2/2] mtd: spi-nor: use spi-mem dirmap API
  2020-02-16 23:03   ` Tudor.Ambarus
@ 2020-02-17 18:43     ` Sergei Shtylyov
  0 siblings, 0 replies; 8+ messages in thread
From: Sergei Shtylyov @ 2020-02-17 18:43 UTC (permalink / raw)
  To: Tudor.Ambarus; +Cc: richard, linux-mtd, vigneshr, miquel.raynal

On 02/17/2020 02:03 AM, Tudor.Ambarus@microchip.com wrote:

> Looks good. Few nits below that I can fix when applying. Let me know if 
> you're ok with the changes.
> 
> On Monday, January 27, 2020 10:29:06 PM EET Sergei Shtylyov wrote:
>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the
>> content is safe
>>
>> Make use of the spi-mem direct mapping API to let advanced controllers
>> optimize read/write operations when they support direct mapping.
>>
>> Based on the original patch by Boris Brezillon
>> <boris.brezillon@bootlin.com>.
>>
>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
>>
>> ---
>> Changes in version 4:
>> - moved the spi_mem_dirmap_{read|write}() calls closer to the ending of
>>   spi_nor_{read|write}(), adapting to the chnages caused by the new patch
>>   splitting spi_nor_spimem_xfer_data()...
>>
>> Changes in version 3:
>> - simplified the way spi_mem_dirmap_{read|write}() are called;
>> - added Boris' tag.
>>
>> Changes in version 2:
>> - moved the spi_mem_dirmap_{read|write}() calls from spi_nor_{read|write}()
>> to spi_nor_spimem_{read|write}_data().
>>
>>  drivers/mtd/spi-nor/spi-nor.c |   97
>> ++++++++++++++++++++++++++++++++++++++---- include/linux/mtd/spi-nor.h   | 
>>   5 ++
>>  2 files changed, 93 insertions(+), 9 deletions(-)
>>
>> Index: linux/drivers/mtd/spi-nor/spi-nor.c
>> ===================================================================
>> --- linux.orig/drivers/mtd/spi-nor/spi-nor.c
>> +++ linux/drivers/mtd/spi-nor/spi-nor.c
[...]
>> @@ -319,14 +320,23 @@ static ssize_t spi_nor_spimem_read_data(
>>
>>         usebouncebuf = spi_nor_spimem_bounce(nor, &op);
>>
>> -       error = spi_nor_spimem_exec_op(nor, &op);
>> -       if (error)
>> -               return error;
>> +       if (nor->dirmap.rdesc) {
>> +               nbytes = spi_mem_dirmap_read(nor->dirmap.rdesc, op.addr.val,
> 
> op.data.nbytes = spi_mem_dirmap_read() ?

   op.data.nbytes is *unsigned int*, spi_mem_dirmap_read() returns ssize_t.

> This way we can get rid of the local variable nbytes.

   op.data.nbytes can't carry the error codes, not even supposed to be of a signed
type...

[...]
>> @@ -379,11 +390,19 @@ static ssize_t spi_nor_spimem_write_data
>>         if (usebouncebuf)
>>                 memcpy(nor->bouncebuf, buf, op.data.nbytes);
>>
>> -       error = spi_nor_spimem_exec_op(nor, &op);
>> -       if (error)
>> -               return error;
>> +       if (nor->dirmap.wdesc) {
>> +               nbytes = spi_mem_dirmap_write(nor->dirmap.wdesc,
>> op.addr.val, +                                          op.data.nbytes,

> I'll align this to "("

   Sorry about missing that. Copy&paste from the read function played its role here...

> op.data.nbytes = spi_mem_dirmap_write() ?

   Same comments as in the read function...

> This way we can get rid of the local variable nbytes.
> 
>> op.data.buf.out); +               if (nbytes < 0)
>> +                       return nbytes;
> 
> you already return nbytes below, we can drop this check.

   Yeah, sorry about that! We've already copied from the bounce buffer

>> +       } else {
>> +               error = spi_nor_spimem_exec_op(nor, &op);
>> +               if (error)
>> +                       return error;
>> +               nbytes = op.data.nbytes;
>> +       }
>>
>> -       return op.data.nbytes;
>> +       return nbytes;
>>  }
> 
> Cheers,
> ta

MBR, Sergei

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^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2020-02-17 18:44 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-01-27 20:23 [PATCH v4 0/2] mtd: spi-nor: use spi-mem dirmap API Sergei Shtylyov
2020-01-27 20:28 ` [PATCH v4 1/2] mtd: spi-nor: split spi_nor_spimem_xfer_data() Sergei Shtylyov
2020-01-28  6:50   ` Boris Brezillon
2020-02-16 22:40   ` Tudor.Ambarus
2020-02-17 17:47     ` Sergei Shtylyov
2020-01-27 20:29 ` [PATCH v4 2/2] mtd: spi-nor: use spi-mem dirmap API Sergei Shtylyov
2020-02-16 23:03   ` Tudor.Ambarus
2020-02-17 18:43     ` Sergei Shtylyov

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