From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>
Subject: Re: [PATCH V2 1/3] iommu/arm-smmu: Add pm_runtime/sleep ops
Date: Wed, 8 Feb 2017 13:52:53 +0000
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To: Sricharan <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, mathieu.poirier-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, linux-arm-msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, sboyd-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
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On Wed, Feb 08, 2017 at 07:15:37PM +0530, Sricharan wrote:
> >Clocks are not architectural, so it only makes sense to associate them
> >with an implementation-specific compatible string. There's also no
> 
> ok, it for this the QCOM specific implementation binding is tried(going to).
> 
> >guarantee that different microarchitectures have equivalent internal
> >clock domains - I'm not sure if "the SMMU's underlying bus access" is
> >meant to refer to accesses *by* the SMMU, i.e. page table walks,
> >accesses *through* the SMMU by upstream masters, or both
> 
> In the above QCOM case, it is actually both. Its the same path for both the
> page table walker and upstream masters.
> 
> >differences are rather significant. I'd also note that an MMU-500
> >configuration may have up to *33* clocks.
> >
> >Either way, the QCOM implementation deserves its own compatible if only
> >for the sake of the imp-def gaps in the architecture (e.g. FSR.SS
> >behaviour WRT to IRQs as touched upon in the other thread).
> >
> 
> Ok, slightly unclear, so you mean then *clocks* are not good enough reason
> to have a new compatible ?

I beleive Robin's point was even if the clocks didn't matter, there are
other reasons we should have the QCOM-specific compatible string.

So we should have one regardless.

Thanks,
Mark.