On Fri, Oct 29, 2021 at 8:36 AM Joel Stanley [off-list ref] wrote:

On Thu, 28 Oct 2021 at 14:57, Arnd Bergmann [off-list ref] wrote:

quoted

On Thu, Oct 28, 2021 at 4:19 PM Lukas Bulwahn [off-list ref] wrote:

quoted

There is no and never was a Kconfig for ARM_ERRATA_794072 in the kernel
tree. So, there is no need to select ARM_ERRATA_794072 in
./arch/arm/mach-npcm/Kconfig.

Simply drop selecting the non-existing ARM_ERRATA_794072.

This issue was discovered with ./scripts/checkkconfigsymbols.py.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
---

Could this be a typo? Maybe we need to enable a different errata workaround
here, or maybe that code is actually needed and has to get sent.

Doing some searching, u-boot had a workaround for something called
ARM_ERRATA_794072.

https://github.com/u-boot/u-boot/commit/f71cbfe3ca5d2ad20159871700e8e248c8818ba8

Lore has the review history for that patch:

https://lore.kernel.org/all/6be32e0b5b454ed7b609317266a8e798@BLUPR03MB358.namprd03.prod.outlook.com/ (local)

It looks like it's the same workaround as ARM_ERRATA_742230, which the
kernel does implement.

It would be good to hear from the Nuvoton people, or an Arm person.

I will happily update the patch to select ARM_ERRATA_742230 instead of
the dead non-existing ARM_ERRATA_794072.

In contrast to the current patch that basically only cleans up "dead
config" and has no effective functional change, the new patch would
change the behaviour. I cannot test this patch (beyond some basic
compile test) on the hardware; so, we certainly need someone to have
that hardware, knows how to test it or confirm otherwise that we
should select the ARM_ERRATA_742230 fix for this hardware.

The current patch should be subsumed by the new patch; the submission
of the new patch is deferred until that person shows up. Let's see.

Lukas

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