Re: [PATCH v2] powerpc/xive: Fix bogus error code returned by OPAL

[Greg Kurz <groug@kaod.org>]

On Thu, 12 Sep 2019 07:30:49 +0000
Sasha Levin <sashal@kernel.org> wrote:

> Hi,
> 
> [This is an automated email]
> 
> This commit has been processed because it contains a -stable tag.
> The stable tag indicates that it's relevant for the following trees: 4.12+
> 
> The bot has tested the following trees: v5.2.14, v4.19.72, v4.14.143.
> 
> v5.2.14: Build OK!
> v4.19.72: Failed to apply! Possible dependencies:
>     75d9fc7fd94e ("powerpc/powernv: move OPAL call wrapper tracing and interrupt handling to C")
> 

This is the only dependency indeed.

> v4.14.143: Failed to apply! Possible dependencies:
>     104daea149c4 ("kconfig: reference environment variables directly and remove 'option env='")
>     21c54b774744 ("kconfig: show compiler version text in the top comment")
>     315bab4e972d ("kbuild: fix endless syncconfig in case arch Makefile sets CROSS_COMPILE")
>     3298b690b21c ("kbuild: Add a cache for generated variables")
>     4e56207130ed ("kbuild: Cache a few more calls to the compiler")
>     75d9fc7fd94e ("powerpc/powernv: move OPAL call wrapper tracing and interrupt handling to C")
>     8f2133cc0e1f ("powerpc/pseries: hcall_exit tracepoint retval should be signed")
>     9a234a2e3843 ("kbuild: create directory for make cache only when necessary")
>     d677a4d60193 ("Makefile: support flag -fsanitizer-coverage=trace-cmp")
>     e08d6de4e532 ("kbuild: remove kbuild cache")
>     e17c400ae194 ("kbuild: shrink .cache.mk when it exceeds 1000 lines")
>     e501ce957a78 ("x86: Force asm-goto")
>     e9666d10a567 ("jump_label: move 'asm goto' support test to Kconfig")
> 

That's quite a lot of patches to workaround a hard to hit skiboot bug.
As an alternative, the patch can be backported so that it applies the
following change:

-OPAL_CALL(opal_xive_allocate_irq,              OPAL_XIVE_ALLOCATE_IRQ);
+OPAL_CALL(opal_xive_allocate_irq_raw,          OPAL_XIVE_ALLOCATE_IRQ);

to "arch/powerpc/platforms/powernv/opal-wrappers.S"
instead of "arch/powerpc/platforms/powernv/opal-call.c" .

BTW, this could also be done for 4.19.y .

> 
> NOTE: The patch will not be queued to stable trees until it is upstream.
> 
> How should we proceed with this patch?
> 

Michael ?

> --
> Thanks,
> Sasha