Hi Andy, On 7/11/2018 5:10 AM, Andy Strohman wrote: > On Tue, Jul 3, 2018 at 11:36 PM, Sricharan R <sricharan@xxxxxxxxxxxxxx> wrote: >> 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 > > Hi Sricharan, > > I just want to thank you for your help and suggestions. I wasn't > able to get it working quickly, so I have to move on to other things. > If/when I get this working, I'll be sure to let you know what I did. > Sure. Me too would try this (kexec without no_cpus=1) and let you know. At the moment, little busy with few other things. But would surely mark this in my next to-do and comeback. 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
