Hi Andy, > > That said, the current code mach-qcom/platsmp.c does not implement the > cpu_kill callback. Even for a hotplug its just a wfi(). While doing > a wfi() is going to work for hotplug, it would not for the kexec, since > the cpu's were never put it reset state and waking them would simply fail. > > That means we need to have the complement to kpssv2_release_secondary > implemented for cpu_kill callback. I will try to write down the exact > sequence from programming guide and give here. > Please look at the code in drivers/soc/qcom/spm.c that controls the sequence of cpu 'c' state during the cpuidle. spm block is the one that takes care of powerdown/up sequence of the cpu after 'wfi' . Similar thing needs to be then done for cpu_kill if we expect a 'cpu' to be powercollapsed and to be brought back during the kexec kernel reboot. Also, please have a look at https://source.codeaurora.org/quic/la/kernel/msm-4.4/tree/arch/arm/mach-msm/platsmp.c?h=LA.HB.1.1.5.c1, old non-dt code that is having the cpu_kill back. When no PM, it simply is a WFI. Regards, Sricharan -- "QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
