Re: [PATCH V10 3/4] mmc: sdhci: Add ADMA3 DMA support for V4 enabled host

From: Thierry Reding
Date: Wed Jan 23 2019 - 04:15:39 EST


On Tue, Jan 22, 2019 at 11:56:32AM -0800, Sowjanya Komatineni wrote:
> Below are the supported DMA types in Host Control1 Register
> with Version 4 enable
> b'00 - SDMA
> b'01 - Not Used
> b'10 - ADMA2
> b'11 - ADMA2 or ADMA3
>
> ADMA3 uses Command Descriptor to issue an SD command.
> A multi-block data transfer is performed by using a pair of CMD
> descriptor and ADMA2 descriptor.
>
> ADMA3 performs multiple of multi-block data transfer by using
> Integrated Descriptor which is more suitable for Command Queuing
> to fetch both Command and Transfer descriptors.
>
> Host Capabilities register indiactes the supports of ADMA3 DMA.
>
> Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
> ---
> [V10]: Changes are same as V9 except this series has SDHCI core changes
> into seperate patch
>
> drivers/mmc/host/sdhci.c | 9 ++++++++-
> drivers/mmc/host/sdhci.h | 2 ++
> 2 files changed, 10 insertions(+), 1 deletion(-)

Reviewed-by: Thierry Reding <treding@xxxxxxxxxx>

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