[PATCH] spi: davinci: Use correct length parameter to dma_map_single calls

[PATCH] spi: davinci: Use correct length parameter to dma_map_single calls

[Michael Williamson]

The davinci spi driver provides an option to use DMA transfers for
data.  In the dma_map_single() call, the driver is passing the
number of words to be transfered for the mapping size.  It should
be the number of bytes.

Signed-off-by: Michael Williamson <michael.williamson-wZX4cNJlHJ2sVWG7oymsAA@public.gmane.org>
---
Note: I only have 8 bit devices to test with, so I can only confirm this
patch does not break such a configuration.

 drivers/spi/davinci_spi.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c
index 166a879..037ba82 100644
--- a/drivers/spi/davinci_spi.c
+++ b/drivers/spi/davinci_spi.c
@@ -591,10 +591,10 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
 
 		if (t->tx_buf) {
 			t->tx_dma = dma_map_single(&spi->dev, (void *)t->tx_buf,
-						dspi->wcount, DMA_TO_DEVICE);
+						t->len, DMA_TO_DEVICE);
 			if (dma_mapping_error(&spi->dev, t->tx_dma)) {
 				dev_dbg(sdev, "Unable to DMA map %d bytes"
-						"TX buffer\n", dspi->wcount);
+						"TX buffer\n", t->len);
 				return -ENOMEM;
 			}
 		}
@@ -624,7 +624,7 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
 
 		if (t->rx_buf) {
 			rx_buf = t->rx_buf;
-			rx_buf_count = dspi->rcount;
+			rx_buf_count = t->len;
 		} else {
 			rx_buf = dspi->rx_tmp_buf;
 			rx_buf_count = sizeof(dspi->rx_tmp_buf);
@@ -636,7 +636,7 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
 			dev_dbg(sdev, "Couldn't DMA map a %d bytes RX buffer\n",
 								rx_buf_count);
 			if (t->tx_buf)
-				dma_unmap_single(NULL, t->tx_dma, dspi->wcount,
+				dma_unmap_single(NULL, t->tx_dma, t->len,
 								DMA_TO_DEVICE);
 			return -ENOMEM;
 		}
@@ -675,7 +675,7 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
 	if (spicfg->io_type == SPI_IO_TYPE_DMA) {
 
 		if (t->tx_buf)
-			dma_unmap_single(NULL, t->tx_dma, dspi->wcount,
+			dma_unmap_single(NULL, t->tx_dma, t->len,
 								DMA_TO_DEVICE);
 
 		dma_unmap_single(NULL, t->rx_dma, rx_buf_count,
-- 
1.7.0.4

[PATCH] spi: davinci: Support DMA transfers larger than 65535 words

[Michael Williamson]

The current davinci SPI driver, in DMA mode, is limited to 65535
words for a single transfer.  Modify the driver by configuring a
3 dimensional EDMA transfer to support up to 65535x65535
words.

Signed-off-by: Michael Williamson <michael.williamson-wZX4cNJlHJ2sVWG7oymsAA@public.gmane.org>
---
This patch is an attempt to address the issue raised here:

http://comments.gmane.org/gmane.linux.davinci/20581

Tested with:
dd if=/dev/mtd7 of=/tmp/test.1K bs=1024 count=1024
dd if=/dev/mtd7 of=/tmp/test.64K bs=65536 count=16
dd if=/dev/mtd7 of=/tmp/test.128K bs=131072 count=8
md5sum /tmp/test*

 drivers/spi/davinci_spi.c |   33 +++++++++++++++++++++++++--------
 1 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c
index 037ba82..411cc32 100644
--- a/drivers/spi/davinci_spi.c
+++ b/drivers/spi/davinci_spi.c
@@ -571,6 +571,7 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
 		unsigned long tx_reg, rx_reg;
 		struct edmacc_param param;
 		void *rx_buf;
+		int b, c;
 
 		dma = &dspi->dma;
 
@@ -599,14 +600,30 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
 			}
 		}
 
+		/*
+		 * If number of words is greater than 65535, then we need
+		 * to configure a 3 dimension transfer.  Use the BCNTRLD
+		 * feature to allow for transfers that aren't even multiples
+		 * of 65535 (or any other possible b size) by first transferring
+		 * the remainder amount then grabbing the next N blocks of
+		 * 65535 words.
+		 */
+
+		c = dspi->wcount/(SZ_64K-1);	/* N 65535 count Blocks */
+		b = dspi->wcount-c*(SZ_64K-1);	/* Remainder */
+		if (b)
+			c++;
+		else
+			b = SZ_64K-1;
+
 		param.opt = TCINTEN | EDMA_TCC(dma->tx_channel);
 		param.src = t->tx_buf ? t->tx_dma : tx_reg;
-		param.a_b_cnt = dspi->wcount << 16 | data_type;
+		param.a_b_cnt = b << 16 | data_type;
 		param.dst = tx_reg;
 		param.src_dst_bidx = t->tx_buf ? data_type : 0;
-		param.link_bcntrld = 0xffff;
-		param.src_dst_cidx = 0;
-		param.ccnt = 1;
+		param.link_bcntrld = 0xffffffff;
+		param.src_dst_cidx = t->tx_buf ? data_type : 0;
+		param.ccnt = c;
 		edma_write_slot(dma->tx_channel, &param);
 		edma_link(dma->tx_channel, dma->dummy_param_slot);
 
@@ -643,12 +660,12 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
 
 		param.opt = TCINTEN | EDMA_TCC(dma->rx_channel);
 		param.src = rx_reg;
-		param.a_b_cnt = dspi->rcount << 16 | data_type;
+		param.a_b_cnt = b << 16 | data_type;
 		param.dst = t->rx_dma;
 		param.src_dst_bidx = (t->rx_buf ? data_type : 0) << 16;
-		param.link_bcntrld = 0xffff;
-		param.src_dst_cidx = 0;
-		param.ccnt = 1;
+		param.link_bcntrld = 0xffffffff;
+		param.src_dst_cidx = (t->rx_buf ? data_type : 0) << 16;
+		param.ccnt = c;
 		edma_write_slot(dma->rx_channel, &param);
 
 		if (pdata->cshold_bug)
-- 
1.7.0.4

Re: [PATCH] spi: davinci: Support DMA transfers larger than 65535 words

[Stefano Babic]

On 03/13/2011 03:34 PM, Michael Williamson wrote:
> The current davinci SPI driver, in DMA mode, is limited to 65535
> words for a single transfer.  Modify the driver by configuring a
> 3 dimensional EDMA transfer to support up to 65535x65535
> words.
> 
> Signed-off-by: Michael Williamson <michael.williamson-wZX4cNJlHJ2sVWG7oymsAA@public.gmane.org>
> ---
> This patch is an attempt to address the issue raised here:
> 
> http://comments.gmane.org/gmane.linux.davinci/20581
> 

Thanks to fix this issue ! Tested on a OMAP-L138 board.

Tested-by: Stefano Babic <sbabic-ynQEQJNshbs@public.gmane.org>

Best regards,
Stefano Babic

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Re: [PATCH] spi: davinci: Support DMA transfers larger than 65535 words

[Sergei Shtylyov]

Hello.

On 13-03-2011 17:34, Michael Williamson wrote:

> The current davinci SPI driver, in DMA mode, is limited to 65535
> words for a single transfer.  Modify the driver by configuring a
> 3 dimensional EDMA transfer to support up to 65535x65535
> words.

> Signed-off-by: Michael Williamson<michael.williamson-wZX4cNJlHJ2sVWG7oymsAA@public.gmane.org>
[...]

> diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c
> index 037ba82..411cc32 100644
> --- a/drivers/spi/davinci_spi.c
> +++ b/drivers/spi/davinci_spi.c
[...]
> @@ -599,14 +600,30 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
>   			}
>   		}
>
> +		/*
> +		 * If number of words is greater than 65535, then we need
> +		 * to configure a 3 dimension transfer.  Use the BCNTRLD
> +		 * feature to allow for transfers that aren't even multiples
> +		 * of 65535 (or any other possible b size) by first transferring
> +		 * the remainder amount then grabbing the next N blocks of
> +		 * 65535 words.
> +		 */
> +
> +		c = dspi->wcount/(SZ_64K-1);	/* N 65535 count Blocks */
> +		b = dspi->wcount-c*(SZ_64K-1);	/* Remainder */

    The driver style (and general Linux kernel style) assumes spaces around 
operators.

WRB, Sergei

Re: [PATCH] spi: davinci: Support DMA transfers larger than 65535 words

[Michael Williamson]

On 3/14/2011 6:25 AM, Sergei Shtylyov wrote:

> Hello.
>
> On 13-03-2011 17:34, Michael Williamson wrote:
>
>> The current davinci SPI driver, in DMA mode, is limited to 65535
>> words for a single transfer.  Modify the driver by configuring a
>> 3 dimensional EDMA transfer to support up to 65535x65535
>> words.
>
>> Signed-off-by: Michael Williamson<michael.williamson-wZX4cNJlHJ2sVWG7oymsAA@public.gmane.org>
> [...]
>
>> diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c
>> index 037ba82..411cc32 100644
>> --- a/drivers/spi/davinci_spi.c
>> +++ b/drivers/spi/davinci_spi.c
> [...]
>> @@ -599,14 +600,30 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
>>               }
>>           }
>>
>> +        /*
>> +         * If number of words is greater than 65535, then we need
>> +         * to configure a 3 dimension transfer.  Use the BCNTRLD
>> +         * feature to allow for transfers that aren't even multiples
>> +         * of 65535 (or any other possible b size) by first transferring
>> +         * the remainder amount then grabbing the next N blocks of
>> +         * 65535 words.
>> +         */
>> +
>> +        c = dspi->wcount/(SZ_64K-1);    /* N 65535 count Blocks */
>> +        b = dspi->wcount-c*(SZ_64K-1);    /* Remainder */
>
>    The driver style (and general Linux kernel style) assumes spaces around operators.



Sure enough.  I am relying on checkpatch.pl too much.  I will fix and
re-post.  Thanks for the style check.

>
> WRB, Sergei





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Re: [PATCH] spi: davinci: Use correct length parameter to dma_map_single calls

[Grant Likely]

On Sun, Mar 13, 2011 at 10:34:21AM -0400, Michael Williamson wrote:
> The davinci spi driver provides an option to use DMA transfers for
> data.  In the dma_map_single() call, the driver is passing the
> number of words to be transfered for the mapping size.  It should
> be the number of bytes.
> 
> Signed-off-by: Michael Williamson <michael.williamson-wZX4cNJlHJ2sVWG7oymsAA@public.gmane.org>

Applied, thanks

g.

> ---
> Note: I only have 8 bit devices to test with, so I can only confirm this
> patch does not break such a configuration.
> 
>  drivers/spi/davinci_spi.c |   10 +++++-----
>  1 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c
> index 166a879..037ba82 100644
> --- a/drivers/spi/davinci_spi.c
> +++ b/drivers/spi/davinci_spi.c
> @@ -591,10 +591,10 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
>  
>  		if (t->tx_buf) {
>  			t->tx_dma = dma_map_single(&spi->dev, (void *)t->tx_buf,
> -						dspi->wcount, DMA_TO_DEVICE);
> +						t->len, DMA_TO_DEVICE);
>  			if (dma_mapping_error(&spi->dev, t->tx_dma)) {
>  				dev_dbg(sdev, "Unable to DMA map %d bytes"
> -						"TX buffer\n", dspi->wcount);
> +						"TX buffer\n", t->len);
>  				return -ENOMEM;
>  			}
>  		}
> @@ -624,7 +624,7 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
>  
>  		if (t->rx_buf) {
>  			rx_buf = t->rx_buf;
> -			rx_buf_count = dspi->rcount;
> +			rx_buf_count = t->len;
>  		} else {
>  			rx_buf = dspi->rx_tmp_buf;
>  			rx_buf_count = sizeof(dspi->rx_tmp_buf);
> @@ -636,7 +636,7 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
>  			dev_dbg(sdev, "Couldn't DMA map a %d bytes RX buffer\n",
>  								rx_buf_count);
>  			if (t->tx_buf)
> -				dma_unmap_single(NULL, t->tx_dma, dspi->wcount,
> +				dma_unmap_single(NULL, t->tx_dma, t->len,
>  								DMA_TO_DEVICE);
>  			return -ENOMEM;
>  		}
> @@ -675,7 +675,7 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
>  	if (spicfg->io_type == SPI_IO_TYPE_DMA) {
>  
>  		if (t->tx_buf)
> -			dma_unmap_single(NULL, t->tx_dma, dspi->wcount,
> +			dma_unmap_single(NULL, t->tx_dma, t->len,
>  								DMA_TO_DEVICE);
>  
>  		dma_unmap_single(NULL, t->rx_dma, rx_buf_count,
> -- 
> 1.7.0.4
>