From: jon-hunter@ti•com (Jon Hunter)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH V6 2/2] dmaengine: add helper function to request a slave DMA channel
Date: Mon, 24 Sep 2012 17:25:47 -0500 [thread overview]
Message-ID: <5060DDEB.4000600@ti.com> (raw)
In-Reply-To: <1347938035.1943.162.camel@vkoul-udesk3>
Hi Vinod,
On 09/17/2012 10:13 PM, Vinod Koul wrote:
> On Mon, 2012-09-17 at 23:36 +0100, Russell King - ARM Linux wrote:
>>>
>>> I believe that Jon is on vacation this week, so if this is the only issue
>>> holding up the merge, maybe you can change this in his patch directly, or
>>> I can send an updated version if you prefer.
>>
>> I worry that too much is going on here too quickly. We have some people
>> working on changing the way DMA engine selects channels. Meanwhile we
>> have other people trying to create an OF DMA engine API.
>>
>> It seems that Vinod's working on a way for platforms to specify bindings
>> to the DMA engine code, and the DMA engine code itself selects the
>> appropriate channel. This patch, on the other hand, introduces a set of
>> translation functions which need to be provided by platform code,
>> which returns the dma_chan pointer.
>>
>> This sounds like a recipe for a total abortion of interfaces. Only one
>> of those two activities should be going on at any one time, or if they
>> have to occur, they need coordination so that the we don't end up with
>> two totally different schemes.
>>
>> In the mad rush to DTify everything, don't make hasty decisions, because
>> it is very difficult to change it later - especially something like this
>> which defines how DT encodes this information.
> We discussed this in KS and IMHO we need to merge these two approaches.
>
> For DT bindings, I think the binding itself shouldn't change based on my
> work but I would like these same bindings to help build the DMA engine
> code mappings.
>
> Now would it make sense to NOT merge these changes for 3.7 and postpone
> to 3.8. I can host these patches on a topic branch and merge them when
> we are ready. I plan to spend some good amount of time on my work this
> week so we should be ready pretty soon.
> One these changes are merged, users can start moving to this scheme.
I just wanted to see how things are progressing your side. Did you
create a topic branch for this? If so let me know where I can find it, I
did not find a branch on your infradead git tree.
I wanted to pull in the latest patches for some testing.
Cheers
Jon
next prev parent reply other threads:[~2012-09-24 22:25 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-14 22:41 [PATCH V6 0/2] of: Add generic device tree DMA helpers Jon Hunter
2012-09-14 22:41 ` [PATCH V6 1/2] " Jon Hunter
2012-09-14 22:46 ` Stephen Warren
2012-09-15 0:14 ` Russell King - ARM Linux
2012-09-17 20:42 ` Arnd Bergmann
2012-09-17 23:06 ` David Brown
2012-09-18 12:50 ` Arnd Bergmann
2012-09-18 22:19 ` Mitch Bradley
2012-09-18 22:32 ` Russell King - ARM Linux
2012-09-19 11:09 ` Arnd Bergmann
2012-09-19 14:40 ` Mitch Bradley
2012-09-19 13:52 ` Matt Porter
2012-09-19 14:07 ` Matt Porter
2012-09-19 14:24 ` Arnd Bergmann
2012-09-19 14:36 ` Rob Herring
2012-09-19 14:40 ` Matt Porter
2012-09-19 14:50 ` Arnd Bergmann
2012-09-19 21:25 ` Mitch Bradley
2012-09-19 14:10 ` Rob Herring
2012-09-14 22:41 ` [PATCH V6 2/2] dmaengine: add helper function to request a slave DMA channel Jon Hunter
2012-09-17 3:33 ` Vinod Koul
2012-09-17 11:59 ` Arnd Bergmann
2012-09-17 22:36 ` Russell King - ARM Linux
2012-09-18 3:13 ` Vinod Koul
2012-09-18 13:21 ` Matt Porter
2012-09-18 15:20 ` Arnd Bergmann
2012-09-18 18:10 ` Russell King - ARM Linux
2012-09-24 22:25 ` Jon Hunter [this message]
2012-09-25 4:35 ` Vinod Koul
2012-10-16 2:43 ` Shawn Guo
2012-10-16 2:39 ` Vinod Koul
2012-11-09 20:01 ` Jon Hunter
2012-11-16 1:37 ` Vinod Koul
2012-11-16 8:39 ` Nicolas Ferre
2012-11-16 15:45 ` Jon Hunter
2012-11-28 17:06 ` Vinod Koul
2012-12-19 17:12 ` Jon Hunter
2012-12-20 14:57 ` Vinod Koul
2012-09-18 3:00 ` Vinod Koul
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