[PATCH v7 3/3] ARM: Check if a CPU has gone offline

[Rob Herring]

On Fri, Apr 25, 2014 at 12:27 PM, Ashwin Chaugule
<ashwin.chaugule at linaro.org> wrote:
> PSCIv0.2 adds a new function called AFFINITY_INFO, which
> can be used to query if a specified CPU has actually gone
> offline. Calling this function via cpu_kill ensures that
> a CPU has quiesced after a call to cpu_die.
>
> Signed-off-by: Ashwin Chaugule <ashwin.chaugule at linaro.org>
> Reviewed-by: Rob Herring <robh at kernel.org>
> ---
>  arch/arm/kernel/psci_smp.c | 32 ++++++++++++++++++++++++++++++++
>  include/uapi/linux/psci.h  |  5 +++++
>  2 files changed, 37 insertions(+)

[...]

> +retry_once:
> +       err = psci_ops.affinity_info(cpu_logical_map(cpu), 0);
> +
> +       if (err != PSCI_AFFINITY_INFO_RET_OFF) {
> +               if (!retry++) {
> +                       msleep(100);

It would be better to sleep 10ms 10 times rather than a single 100ms
sleep. And please do this with a loop rather than a goto.

Rob