Re: [Linaro-acpi] [PATCH v7 3/3] ARM: Check if a CPU has gone offline

On Fri, Apr 25, 2014 at 12:27 PM, Ashwin Chaugule ashwin.chaugule@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@linaro.org Reviewed-by: Rob Herring robh@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