Hi Ram, On 05/28/2016 05:36 AM, Ram Pai wrote: > On Tue, May 24, 2016 at 06:45:12PM +0530, Shreyas B. Prabhu wrote: [snip] >> @@ -230,11 +236,18 @@ static DEVICE_ATTR(fastsleep_workaround_applyonce, >> 0600, >> show_fastsleep_workaround_applyonce, >> store_fastsleep_workaround_applyonce); >> >> +/* >> + * First deep stop state. Used to figure out when to save/restore >> + * hypervisor context. >> + */ >> +u64 pnv_first_deep_stop_state; > > maybe this has to be intialized to some correct default value? > > It there a gaurantee that OPAL_PM_STOP_INST_FAST is set only when > CPU_FTR_ARCH_300 is supported? >
Stop instruction is newly introduced in POWER ISA v3.0. So it is guaranteed that OPAL_PM_STOP_INST_FAST is set only when CPU_FTR_ARCH_300 is supported. So the scenario you've described below will not arise. > if cpu_has_feature(CPU_FTR_ARCH_300) is not true, than > pnv_first_deep_stop_state will be not be initialized. > > And if supported_cpuidle_states > has OPAL_PM_STOP_INST_FAST flag set, than power_stop0 is called which > will blindly use pnv_first_deep_stop_state thinking it is initialized to > something sane. > Thanks, Shreyas
