From: Michael Williamson <michael.williamson-wZX4cNJlHJ2sVWG7oymsAA@public.gmane.org>
To: Sergei Shtylyov <sshtylyov-Igf4POYTYCDQT0dZR+AlfA@public.gmane.org>
Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org,
davinci-linux-open-source-VycZQUHpC/PFrsHnngEfi1aTQe2KTcn/@public.gmane.org,
dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Subject: Re: [PATCH] spi: davinci: Support DMA transfers larger than 65535 words
Date: Mon, 14 Mar 2011 07:06:48 -0400 [thread overview]
Message-ID: <4D7DF6C8.2040505@criticallink.com> (raw)
In-Reply-To: <4D7DED07.7020000-Igf4POYTYCDQT0dZR+AlfA@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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next prev parent reply other threads:[~2011-03-14 11:06 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-13 14:34 [PATCH] spi: davinci: Use correct length parameter to dma_map_single calls Michael Williamson
[not found] ` <1300026862-1179-1-git-send-email-michael.williamson-wZX4cNJlHJ2sVWG7oymsAA@public.gmane.org>
2011-03-13 14:34 ` [PATCH] spi: davinci: Support DMA transfers larger than 65535 words Michael Williamson
[not found] ` <1300026862-1179-2-git-send-email-michael.williamson-wZX4cNJlHJ2sVWG7oymsAA@public.gmane.org>
2011-03-14 9:33 ` Stefano Babic
2011-03-14 10:25 ` Sergei Shtylyov
[not found] ` <4D7DED07.7020000-Igf4POYTYCDQT0dZR+AlfA@public.gmane.org>
2011-03-14 11:06 ` Michael Williamson [this message]
2011-03-14 19:18 ` [PATCH] spi: davinci: Use correct length parameter to dma_map_single calls Grant Likely
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