On Wed, 2017-04-12 at 17:16 +0530, Gautham R. Shenoy wrote: > From: "Gautham R. Shenoy" <e...@linux.vnet.ibm.com> > > The idle-exit code assumes that if Timebase is not lost, then neither > are the per-core hypervisor resources lost.
Double negative! How about: The idle-exit code assumes that if the timebase is restored, then the per-core hypervisor resources are also restored. > This was true on POWER8 > where fast-sleep lost only TB but not per-core resources, and winkle > lost both. > > This assumption is not true for POWER9 however, since there can be > states which do not lose timebase but can lose per-core SPRs. > > Hence check if we need to restore the per-core hypervisor state even > if timebase is not lost. I think I understand what you're doing, just seems awkwardly worded. Is this actually what the patch is doing? It seem to be just changing one branch. Mikey > > Signed-off-by: Gautham R. Shenoy <e...@linux.vnet.ibm.com> > --- > arch/powerpc/kernel/idle_book3s.S | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/arch/powerpc/kernel/idle_book3s.S > b/arch/powerpc/kernel/idle_book3s.S > index 9b747e9..6a9bd28 100644 > --- a/arch/powerpc/kernel/idle_book3s.S > +++ b/arch/powerpc/kernel/idle_book3s.S > @@ -723,13 +723,14 @@ timebase_resync: > * Use cr3 which indicates that we are waking up with atleast partial > * hypervisor state loss to determine if TIMEBASE RESYNC is needed. > */ > - ble cr3,clear_lock > + ble cr3,.Ltb_resynced > /* Time base re-sync */ > bl opal_resync_timebase; > /* > - * If waking up from sleep, per core state is not lost, skip to > - * clear_lock. > + * If waking up from sleep (POWER8), per core state > + * is not lost, skip to clear_lock. > */ > +.Ltb_resynced: > blt cr4,clear_lock > > /*
