Content-Class: urn:content-classes:message
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 8BIT
Subject: RE: [PATCH 05/11] mmc/host: add context parameter for DMA_SLAVEand DMA_CYCLIC
Date: Fri, 3 Feb 2012 10:36:04 -0800
Message-ID: <0CE8B6BE3C4AD74AB97D9D29BD24E55202872788@CORPEXCH1.na.ads.idt.com>
In-Reply-To: <20120203170153.GA15891@flint.arm.linux.org.uk>
Thread-Topic: [PATCH 05/11] mmc/host: add context parameter for DMA_SLAVEand DMA_CYCLIC
Thread-Index: AczilarCTj9K9aq0RpKtmk8F62tXUwACdFEA
References: <1328218341-31436-1-git-send-email-alexandre.bounine@idt.com> <1328218341-31436-6-git-send-email-alexandre.bounine@idt.com> <4F2BA6C0.10100@stericsson.com> <0CE8B6BE3C4AD74AB97D9D29BD24E5520287270D@CORPEXCH1.na.ads.idt.com> <20120203170153.GA15891@flint.arm.linux.org.uk>
From: "Bounine, Alexandre" <Alexandre.Bounine@idt.com>
To: Russell King <rmk@arm.linux.org.uk>
CC: Ulf Hansson <ulf.hansson@stericsson.com>, <vinod.koul@intel.com>,
        <dan.j.williams@intel.com>, <linux-kernel@vger.kernel.org>,
        Nicolas Ferre <nicolas.ferre@atmel.com>, Chris Ball <cjb@laptop.org>,
        Guennadi Liakhovetski <g.liakhovetski@gmx.de>,
        Ian Molton <ian@mnementh.co.uk>,
        Linus Walleij <linus.walleij@linaro.org>,
        Per FORLIN <per.forlin@stericsson.com>,
        "Sascha Hauer" <s.hauer@pengutronix.de>,
        Anton Vorontsov <cbouatmailru@gmail.com>,
        Shawn Guo <shawn.guo@linaro.org>, Wolfram Sang <w.sang@pengutronix.de>,
        Paul Gortmaker <paul.gortmaker@windriver.com>,
        Viresh KUMAR <viresh.kumar@st.com>
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1702
Lines: 50

On Fri, Feb 03, 2012 at 12:02 PM, Russell King wrote:
> 
> On Fri, Feb 03, 2012 at 08:52:07AM -0800, Bounine, Alexandre wrote:
> > If these API changes will be approved I will resubmit these changes
> > as one patch.
> 
> I'd like to suggest an alternative approach, if you still want to add
a
> void * parameter to this.
> 
> 1. A patch which adds this, and convert users over to it:
> 
> static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_sg(
> 	struct dma_chan *chan, struct scatterlist *sg, unsigned sg_len,
> 	enum dma_transfer_direction direction, unsigned long flags)
> {
> 	return chan->device->device_prep_slave_sg(chan, sg, sglen, dir,
> flags);
> }
> 
> 2. Change device->device_prep_slave_sg() to have a new prototype, and
>    update the above inline function to cope with the change.  This API
>    change is then restricted to just the DMA engine code.
> 
> 3. Introduce a new inline function to deal with rapidio slave sg
>    submission.
> 
> This means all drivers which aren't capable of using the special
> rapidio
> features get to ignore the new details about rapidio entirely.
> 

This looks like a great improvement to the original proposal.
I will just add another inline function (with specific type for
parameter)
inside of RapidIO subsystem.

If DMA engine maintainers agree with this approach, I will build a new
patch within next week (changes to existing drivers first, RapidIO to
follow).

Thank you,

Alex.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/