Nicholas Piggin <npig...@gmail.com> writes: > On Wed, 30 Aug 2017 21:25:59 +1000 > Michael Ellerman <m...@ellerman.id.au> wrote: > >> Nicholas Piggin <npig...@gmail.com> writes: >> >> > When stop is executed with EC=ESL=0, it appears to execute like a >> > normal instruction (resuming from NIP when woken by interrupt). >> > So all the save/restore handling can be avoided completely. In >> > particular NV GPRs do not have to be saved, and MSR does not have >> > to be switched back to kernel MSR. >> > >> > So move the test for "lite" sleep states out to power9_idle_stop. >> > >> > Reviewed-by: Gautham R. Shenoy <e...@linux.vnet.ibm.com> >> > Signed-off-by: Nicholas Piggin <npig...@gmail.com> >> > --- >> > arch/powerpc/kernel/idle_book3s.S | 35 ++++++++++++++++++++++++----------- >> > 1 file changed, 24 insertions(+), 11 deletions(-) >> >> This is blowing up for me on mambo: > > Oh this is a known bug in mambo that does not match the hardware. > > You need >= Mambo.7.8.21, or this firmware patch to work around > the issue for old mambos.
As discussed elsewhere this still breaks on new mambo with more than one CPU. So I've dropped it for now. cheers
