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authorGautham R. Shenoy <ego@linux.vnet.ibm.com>2017-05-16 11:49:48 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2017-05-30 07:59:51 +0300
commitf9122ee4f5580194014d4ca72092787ae33f29fb (patch)
tree2b96b25a8067bc3f3f2b2fe01b528d87a025e920 /drivers/cpuidle
parent22c6663dc69a042a7b4158f162582b4b1ba7a4b7 (diff)
downloadlinux-f9122ee4f5580194014d4ca72092787ae33f29fb.tar.xz
cpuidle-powernv: Allow Deep stop states that don't stop time
The current code in the cpuidle-powernv intialization only allows deep stop states (indicated by OPAL_PM_STOP_INST_DEEP) which lose timebase (indicated by OPAL_PM_TIMEBASE_STOP). This assumption goes back to POWER8 time where deep states used to lose the timebase. However, on POWER9, we do have stop states that are deep (they lose hypervisor state) but retain the timebase. Fix the initialization code in the cpuidle-powernv driver to allow such deep states. Further, there is a bug in cpuidle-powernv driver with CONFIG_TICK_ONESHOT=n where we end up incrementing the nr_idle_states even if a platform idle state which loses time base was not added to the cpuidle table. Fix this by ensuring that the nr_idle_states variable gets incremented only when the platform idle state was added to the cpuidle table. Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'drivers/cpuidle')
-rw-r--r--drivers/cpuidle/cpuidle-powernv.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index 12409a519cc5..45eaf06462ae 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -354,6 +354,7 @@ static int powernv_add_idle_states(void)
for (i = 0; i < dt_idle_states; i++) {
unsigned int exit_latency, target_residency;
+ bool stops_timebase = false;
/*
* If an idle state has exit latency beyond
* POWERNV_THRESHOLD_LATENCY_NS then don't use it
@@ -381,6 +382,9 @@ static int powernv_add_idle_states(void)
}
}
+ if (flags[i] & OPAL_PM_TIMEBASE_STOP)
+ stops_timebase = true;
+
/*
* For nap and fastsleep, use default target_residency
* values if f/w does not expose it.
@@ -392,8 +396,7 @@ static int powernv_add_idle_states(void)
add_powernv_state(nr_idle_states, "Nap",
CPUIDLE_FLAG_NONE, nap_loop,
target_residency, exit_latency, 0, 0);
- } else if ((flags[i] & OPAL_PM_STOP_INST_FAST) &&
- !(flags[i] & OPAL_PM_TIMEBASE_STOP)) {
+ } else if (has_stop_states && !stops_timebase) {
add_powernv_state(nr_idle_states, names[i],
CPUIDLE_FLAG_NONE, stop_loop,
target_residency, exit_latency,
@@ -405,8 +408,8 @@ static int powernv_add_idle_states(void)
* within this config dependency check.
*/
#ifdef CONFIG_TICK_ONESHOT
- if (flags[i] & OPAL_PM_SLEEP_ENABLED ||
- flags[i] & OPAL_PM_SLEEP_ENABLED_ER1) {
+ else if (flags[i] & OPAL_PM_SLEEP_ENABLED ||
+ flags[i] & OPAL_PM_SLEEP_ENABLED_ER1) {
if (!rc)
target_residency = 300000;
/* Add FASTSLEEP state */
@@ -414,14 +417,15 @@ static int powernv_add_idle_states(void)
CPUIDLE_FLAG_TIMER_STOP,
fastsleep_loop,
target_residency, exit_latency, 0, 0);
- } else if ((flags[i] & OPAL_PM_STOP_INST_DEEP) &&
- (flags[i] & OPAL_PM_TIMEBASE_STOP)) {
+ } else if (has_stop_states && stops_timebase) {
add_powernv_state(nr_idle_states, names[i],
CPUIDLE_FLAG_TIMER_STOP, stop_loop,
target_residency, exit_latency,
psscr_val[i], psscr_mask[i]);
}
#endif
+ else
+ continue;
nr_idle_states++;
}
out: