Joel Stanley <joel@xxxxxxxxx> writes:
> In commit 900612315788 ("powerpc/powernv/smp: Add busy-wait loop as fall back
> for CPU-Hotplug") the idle code uses generic_check_cpu_restart(), but that
> function is not available when CONFIG_HOTPLUG_CPU is disabled.
>
> arch/powerpc/platforms/powernv/idle.c: In function ‘pnv_cpu_offline’:
> arch/powerpc/platforms/powernv/idle.c:286:11: error: implicit declaration of
> function ‘generic_check_cpu_restart’ [-Werror=implicit-function-declaration]
> while (!generic_check_cpu_restart(cpu)) {
> ^~~~~~~~~~~~~~~~~~~~~~~~~
>
> The callers of pnv_cpu_offline are behind CONFIG_HOTPLUG_CPU, so fix the build
> error by putting this code behind the same gard.
>
> Fixes: 900612315788 ("powerpc/powernv/smp: Add busy-wait loop as fall back for CPU-Hotplug").
> Cc: <stable@xxxxxxxxxxxxxxx> # 4.12
> Signed-off-by: Joel Stanley <joel@xxxxxxxxx>
This was fixed upstream in commit 67d204180886, but I forgot to tag it
for stable.
https://git.kernel.org/torvalds/c/67d204180886
I've just sent mail to stable asking for it to be backported to 4.12.
cheers