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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sat, 6 May 2023 08:43:08 -0700
Message-ID: <CAHk-=wgUiAtiszwseM1p2fCJ+sC4XWQ+YN4TanFhUgvUqjr9Xw@mail.gmail.com>
Subject: Re: [PATCH] iommu: Add Kconfig help text for IOMMU_SVA
To:     Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc:     LKML <linux-kernel@vger.kernel.org>, iommu@lists.linux.dev,
        Jason Gunthorpe <jgg@nvidia.com>,
        Lu Baolu <baolu.lu@linux.intel.com>,
        Joerg Roedel <joro@8bytes.org>,
        Jean-Philippe Brucker <jean-philippe@linaro.com>,
        Robin Murphy <robin.murphy@arm.com>,
        Will Deacon <will@kernel.org>, Raj Ashok <ashok.raj@intel.com>,
        "Tian, Kevin" <kevin.tian@intel.com>, Yi Liu <yi.l.liu@intel.com>,
        "Yu, Fenghua" <fenghua.yu@intel.com>
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On Sat, May 6, 2023 at 6:27=E2=80=AFAM Jacob Pan <jacob.jun.pan@linux.intel=
.com> wrote:
>
> Shared Virtual Addressing (SVA) is not immediately intuitive to people
> who work outside IOMMU subsystem, add some explanation to make it less
> opaque.

So the patch has at least two problems.

The first is that you corrupted the SPDX line.

But the second is that the change from

-       bool
+       bool "Shared Virtual Addressing"

means that now Kconfig *asks* about this thing, which was never the
intent. The other Kconfig options that need it all do a

        select IOMMU_SVA

to get it picked.

I suspect that's why it then causes errors - because now the test
robot can enable the option even in situations where it makes no sense
and doesn't work.

So no, it's not that the option needs a help entry that can be queried
at Kconfig time. It's that the option needs a name that makes sense
and isn't some random jumble of letters that is only understandable to
people who already know exactly what it is.

               Linus