Re: Linux 5.19-rc6

[Linus Torvalds]

On Tue, Jul 12, 2022 at 10:07 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
>
> Same problems as every week.
>
> Building powerpc:allmodconfig ... failed

Ok, this has been going on since -rc1, which is much too long.

>From your patch submission that that was rejected:

> The problem was introduced with commit 41b7a347bf14 ("powerpc: Book3S
> 64-bit outline-only KASAN support") which adds support for KASAN. This
> commit in turn enables DRM_AMD_DC_DCN because KCOV_INSTRUMENT_ALL and
> KCOV_ENABLE_COMPARISONS are no longer enabled. As result, new files are
> compiled which lack the selection of hard-float.

And considering that neither the ppc people nor the drm people seem
interested in fixing this, and it doesn't revert cleanly I think the
sane solution seems to be to just remove PPC64 support for DRM_AMD_DC
entirely.

IOW, does something like this (obviously nor a proper patch, but you
get the idea) fix the ppc build for you?

  @@ -6,7 +6,7 @@ config DRM_AMD_DC
          bool "AMD DC - Enable new display engine"
          default y
          select SND_HDA_COMPONENT if SND_HDA_CORE
  -       select DRM_AMD_DC_DCN if (X86 || PPC64) &&
!(KCOV_INSTRUMENT_ALL && KCOV_ENABLE_COMPARISONS)
  +       select DRM_AMD_DC_DCN if X86 && !(KCOV_INSTRUMENT_ALL &&
KCOV_ENABLE_COMPARISONS)
          help
            Choose this option if you want to use the new display engine
            support for AMDGPU. This adds required support for Vega and

> OF: amba_device_add() failed (-19) for /amba/smc@10100000
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 1 at lib/refcount.c:28 of_platform_bus_create+0x33c/0x3dc
> refcount_t: underflow; use-after-free.

This too has been going on since -rc1, but it's not obvious what caused it.

At a guess, looking around the amba changes, I'm assuming it's

  7719a68b2fa4 ("ARM: 9192/1: amba: fix memory leak in amba_device_try_add()")

Does reverting that commit make it go away?

                    Linus