RE: [PATCH 0/6+1] ARM: EXYNOS4: SYSMMU: Improvements on SYSMMU driver

[Marek Szyprowski]

Hello,

On Tuesday, July 05, 2011 1:38 AM KyongHo Cho wrote:

> On Mon, Jul 4, 2011 at 3:47 PM, Marek Szyprowski
> <m.szyprowski@xxxxxxxxxxx> wrote:
> > Hello,
> >
> > I really don't get why do You persist in creating one monster platform
> > device with resources for ALL SYSMMU/IOMMU controllers that are available
> > on Exynos4 CPU. We (SPRC, see Andrzej's SYSMMU patches) already proposed
> > a clean solution for making the SYSMMU controllers independent of each
> > other as well as making the main SYSMMU driver simpler and more
> > independent of the particular Exynos4 platform definition. In Linux
> > device model if the device/controller exist in the system in more than
> > one instance, there should by one generic driver for it and a set of
> > platform definitions for each instance.
> >
> Did you find this patch? "[PATCH 3/6] ARM: EXYNOS4: SYSMMU"
> I Cced you because it includes your suggestion.

Right, I'm really sorry. It looks that I'm too busy and misunderstood your
patches in a brief look.

> > Here is the link to our SYSMMU updated driver (implementing common
> > iommu API):
> > http://www.spinics.net/lists/linux-samsung-soc/msg04508.html
> > The driver still needs some cleanup, but this has been delayed until
> > the dma-mapping framework update is finished.
> >
> > I also don't get why do you want to keep the completely custom sysmmu
> > driver and implement iommu API on top of it. Is it really required for
> > anything? Mainline kernel is not a place for custom APIs if there is
> > already a common, generic one.
> 
> I did not exposed any custom API.
> The global function in the last patch is just for IOMMU API implemenation.
> The header file in the last patch is not for the device drivers but
> for the IOMMU API implementation.
> Actually, they can be merged into one single file.
> But I just wanted to change the kernel code stepwise.

What about arch/arm/plat-s5p/sysmmu.c ? I didn't notice any commit which 
removes this file. Also both drivers/iommu/exynos4_sysmmu.c and 
drivers/iommu/exynos_iommu.c should be merged together.

Best regards
-- 
Marek Szyprowski
Samsung Poland R&D Center



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