Messages in this thread | | | Date | Thu, 21 Feb 2013 09:29:47 +0100 | From | Philippe De Muyter <> | Subject | Re: [PATCH resent] dma: add the freescale-provided MultiChannel DMA driver |
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Hi Vinod,
On Wed, Feb 20, 2013 at 12:01:47PM +0530, Vinod Koul wrote: > On Mon, Feb 04, 2013 at 06:38:23PM +0100, Philippe De Muyter wrote: > > This patch adds the (cleaned-up) Freescale-provided MultiChannel DMA > > driver for ColdFire M54xx and MPC8220 processors. > > > > This driver is needed for the ethernet FEC driver of the ColdFire > > M547x and M548x processors. > > > > It is not dmaengine-enabled, but that's not needed for the above FEC driver. > > I have however installed it in the driver/dma tree as this IP block is not > > m68k-specific, but freescale-specific, and shared at least between powerpc > > and coldfire parts (possibly arm-parts as well). > > > > The installation in drivers/dma implies a small rule change in > > drivers/Makefile to enter drivers/dma on CONFIG_DMADEVICES instead > > of CONFIG_DMAENGINE. > BIG NAK
Thanks for your answer.
> 1. Please run Checkpath and reread Documentation/CodingStyle, specfically CH4. > Avoid the CamelCase
I had run checkpatch when I made the patch, but CamelCase was not yet searched for at that time. I will look at that.
> 2. If you are not using dmaengine APIs then drivers/dma/ is not a place for you.
What would be the place then for a multi-architecture dma driver. Freescale often reuses the same blocks for its m68k (coldfire), powerpc and arm (iMX) product lines. A dma driver with many similarities is already under the arch/powerpc subtree. I would like to avoid that, because it clearly hurts reusability.
> 3. While glancing at the code, I dont see why you cant use dmaengine APIs?
lack of need (the sole current user of this dma driver is a FEC ethernet driver which uses the current interface), time and expertise. but any help is welcome.
> 4. lastly, am blown off by your own implementation of memcpy, WHY? Kernel is > smarter than you!
I agree, but don't shoot the messenger. I am not the original author, this is freescale code. I only ensured that it compiles and works with current kernels, and suppressed many checkpatch warnings.
Best regards
Philippe
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