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

[Michael Ellerman <mpe@ellerman.id.au>]

Greg Kurz <groug@kaod.org> writes:
> 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.

But it's a large and intrusive change, so we don't want to backport it
just for this.

>> 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 ?

We should do a manual backport for v4.14 and v4.19. Greg do you have
cycles to do that?

cheers