[PATCH] Implements DMA on mmci driver for LPC3250 plateform

Ezequiel Garcia elezegarcia at gmail.com
Wed Jan 23 07:26:29 EST 2013


On Wed, Jan 23, 2013 at 7:11 AM, Gabriele Mondada
<gabriele at precidata.com> wrote:
> Signed-off-by: Gabriele Mondada <gabriele at precidata.com>
> UPDATE: Here is the patch cleaned up and validated with scripts/checkpatch.pl. I also add a check to prevent crashing when DMA is disabled.
> Hi,
> Currently, LPC32xx plateform do not enable DMA on the mmci driver. This makes the driver useless because getting out data from a 64 bytes FIFO by interrupt is not fast enough (at standard SD-card data rate).
> DMA is not enabled because LPC32xx has a bug that prevent DMA to work properly with the MMC controller (silicon bug, I guess). NXP did a patch to workaround this, but it has not been commited on the main branch. The patch is for linux and does not use dmaengine.
> So, I reworked this patch to make it compatible with the last kernel (3.7). Here it is. Have I any chance to see this patch be commited on the main branch?

You can add this sort of description, that's not intended as part of the
commit message after the "---" line and before the diff stat (*).
It's typically used to add a changelog.

See here:

Also, given you seem to be having some problems preparing the patch
I suggest you to watch Greg's talk on submitting first patch:


> ---

(*) here!

> drivers/dma/amba-pl08x.c |   20 ++++++
> drivers/mmc/host/mmci.c  |  159 +++++++++++++++++++++++++++++++++++++++++-----
> drivers/mmc/host/mmci.h  |   12 +++-
> 3 files changed, 174 insertions(+), 17 deletions(-)
> diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
> index d1cc579..728f65f 100644
> --- a/drivers/dma/amba-pl08x.c
> +++ b/drivers/dma/amba-pl08x.c
> @@ -1758,6 +1758,26 @@ static void pl08x_free_virtual_channels(struct dma_device *dmadev)
>         }
> }


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