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

[Michael Williamson <michael.williamson-wZX4cNJlHJ2sVWG7oymsAA@public.gmane.org>]

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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