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From: Daniel Walker <dwalker@fifo99.com>
To: Subhash Jadavani <subhashj@codeaurora.org>
Cc: cjb@laptop.org, linux-mmc@vger.kernel.org,
	linux-arm-msm@vger.kernel.org, davidb@codeaurora.org,
	bryanh@codeaurora.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC] mmc: msm_sdcc: Use SPS BAM as DMA engine
Date: Wed, 23 Mar 2011 06:05:35 -0700	[thread overview]
Message-ID: <1300885535.6117.15.camel@m0nster> (raw)
In-Reply-To: <1300454644-11361-2-git-send-email-subhashj@codeaurora.org>

On Fri, 2011-03-18 at 18:54 +0530, Subhash Jadavani wrote:
> On recent MSMs, ADM (Data Mover) HW is not present
> which means existing SDCC driver can perform data
> transfer in PIO (peripheral IO) mode only.
> But PIO mode requires lot of CPU attention which
> would mean consuming extra CPU MIPS.
> 
> As a replacement on these recent MSMs, there is
> a new DMA HW engine named SPS-BAM (as part of
> Smart Peripheral System of MSM) is added for
> data movement between SDCC core and system memory.
> 
> This patch has done changes in existing MSM SDCC
> driver for using SPS-BAM as DMA engine.

1300+ lines of code might warrant more of a description .. In the
subject you say "DMA engine" but does this use drivers/dma/dmaengine.c ?

> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
> ---
>  drivers/mmc/host/Kconfig        |   10 +
>  drivers/mmc/host/Makefile       |    1 +
>  drivers/mmc/host/msm_sdcc.c     |  929 +++++++++++++++++++++++++++++++++++++--
>  drivers/mmc/host/msm_sdcc.h     |   47 ++
>  drivers/mmc/host/msm_sdcc_dml.c |  303 +++++++++++++
>  drivers/mmc/host/msm_sdcc_dml.h |  120 +++++
>  6 files changed, 1374 insertions(+), 36 deletions(-)
>  create mode 100644 drivers/mmc/host/msm_sdcc_dml.c
>  create mode 100644 drivers/mmc/host/msm_sdcc_dml.h

I'd do at least two patches. One that adds msm_sdcc_dml.[ch] and one
that modifies msm_sdcc.[ch] and the Kconfig and Makefile.

Daniel

  reply	other threads:[~2011-03-23 13:05 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-18 13:24 [RFC] mmc: msm_sdcc: Use SPS BAM as DMA engine Subhash Jadavani
2011-03-18 13:24 ` Subhash Jadavani
2011-03-23 13:05   ` Daniel Walker [this message]
2011-03-24  7:32     ` Subhash Jadavani
2011-03-24 22:45       ` David Brown
2011-03-29  4:30         ` Koul, Vinod
2011-03-24  7:37     ` Subhash Jadavani

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