Re: [RFC PATCH 06/11] iommu: arm-smmu: Remove Calxeda secure mode quirk

From: Andre Przywara <andre.przywara@arm.com>
To: Will Deacon <will@kernel.org>
Cc: Rob Herring <robh@kernel.org>,
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Subject: Re: [RFC PATCH 06/11] iommu: arm-smmu: Remove Calxeda secure mode quirk
Date: Fri, 28 Feb 2020 10:25:56 +0000	[thread overview]
Message-ID: <20200228102556.1dde016e@donnerap.cambridge.arm.com> (raw)
In-Reply-To: <20200228100446.GA2395@willie-the-truck>

On Fri, 28 Feb 2020 10:04:47 +0000
Will Deacon <will@kernel.org> wrote:

Hi,

> On Tue, Feb 25, 2020 at 04:01:54PM -0600, Rob Herring wrote:
> > On Tue, Feb 18, 2020 at 11:20 AM Will Deacon <will@kernel.org> wrote:  
> > >
> > > On Tue, Feb 18, 2020 at 11:13:16AM -0600, Rob Herring wrote:  
> > > > Cc: Will Deacon <will@kernel.org>
> > > > Cc: Robin Murphy <robin.murphy@arm.com>
> > > > Cc: Joerg Roedel <joro@8bytes.org>
> > > > Cc: iommu@lists.linux-foundation.org
> > > > Signed-off-by: Rob Herring <robh@kernel.org>
> > > > ---
> > > > Do not apply yet.  
> > >
> > > Pleeeeease? ;)
> > >  
> > > >  drivers/iommu/arm-smmu-impl.c | 43 -----------------------------------
> > > >  1 file changed, 43 deletions(-)  
> > >
> > > Yes, I'm happy to get rid of this. Sadly, I don't think we can remove
> > > anything from 'struct arm_smmu_impl' because most implementations fall
> > > just short of perfect.
> > >
> > > Anyway, let me know when I can push the button and I'll queue this in
> > > the arm-smmu tree.  
> > 
> > Seems we're leaving the platform support for now, but I think we never
> > actually enabled SMMU support. It's not in the dts either in mainline
> > nor the version I have which should be close to what shipped in
> > firmware. So as long as Andre agrees, this one is good to apply.  
> 
> Andre? Can I queue this one for 5.7, please?

I was wondering how much of a pain it is to keep it in? AFAICS there are other users of the "impl" indirection. If those goes away, I would be happy to let Calxeda go.
But Eric had the magic DT nodes to get the SMMU working, and I used that before, with updating the DT either on flash or dynamically via U-Boot.

So I don't know exactly *how* desperate you are with removing this, or if there are other reasons than "negative diffstat", but if possible I would like to keep it in.

Cheers,
Andre.