Re: [PATCH v11 17/27] iommu/exynos: remove calls to Runtime PM API functions

From: Grant Grundler
Date: Wed Mar 19 2014 - 14:38:12 EST

On Wed, Mar 19, 2014 at 10:30 AM, Tomasz Figa <t.figa@xxxxxxxxxxx> wrote:
> As I said, AFAIK the trend is to get rid of ordering by initcalls and make
> sure that drivers can handle missing dependencies properly, even for
> "services" such as DMA, GPIO, clocks and so on, which after all are provided
> by normal drivers like other.

Ok - I'm not following the general kernel dev trends. initcall()
levels are easy to understand and implement. So I would not be in a
hurry to replace them.

>> ps. I've written IOMMU support for four different IOMMUs on three
>> operating systems (See drivers/parisc for two linux examples). But I
>> still feel like I at best have 80% understanding of how this one is
>> organized/works. Abstract descriptions and convoluted code have been
>> handicapping me (and lack of time to dig further).
> Well, this is one of my concerns with this driver. It isn't easy to read
> (and so review, maintain, extend and debug found issues).

My postscript comment was more to explain why I'm not confident in my
opinion - not a reason to reject the patch series. I still consider
the whole series as a step forward. But I'm not the expert here.

Right now, with ~30 patches posted by the exynos iommu (official?)
maintainer, no one else who has a clue will attempt to fix or clean up
those kinds of problems. i.e. it's useful to enable others to fix
what are essentially unspecified "design pattern" issues.

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