cpupower: Enable disabled Cstates if they are below max latency

cpupower idle-set -D <latency>
currently only disables all C-states that have a higher latency than the
specified <latency>. But if deep sleep states were already disabled and
have a lower latency, they should get enabled again.

For example:
This call:
cpupower idle-set -D 30
disables all C-states with a higher or equal latency than 30.
If one then calls:
cpupower idle-set -D 100
C-states with a latency between 30-99 will get enabled again with this patch
now. It is ensured that only C-states with a latency of 100 and higher are
disabled.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

2 files changed, 16 insertions, 5 deletions

diff --git a/tools/power/cpupower/man/cpupower-idle-set.1 b/tools/power/cpupower/man/cpupower-idle-set.1
index 3e6799d7a79f..580c4e3ea92a 100644
--- a/tools/power/cpupower/man/cpupower-idle-set.1
+++ b/tools/power/cpupower/man/cpupower-idle-set.1
@@ -20,7 +20,9 @@ Disable a specific processor sleep state.
 Enable a specific processor sleep state.
 .TP
 \fB\-D\fR \fB\-\-disable-by-latency\fR <LATENCY>
-Disable all idle states with a equal or higher latency than <LATENCY>
+Disable all idle states with a equal or higher latency than <LATENCY>.
+
+Enable all idle states with a latency lower than <LATENCY>.
 .TP
 \fB\-E\fR \fB\-\-enable-all\fR
 Enable all idle states if not enabled already.
diff --git a/tools/power/cpupower/utils/cpuidle-set.c b/tools/power/cpupower/utils/cpuidle-set.c
index 9a9b7a337d7b..eaea1301e29b 100644
--- a/tools/power/cpupower/utils/cpuidle-set.c
+++ b/tools/power/cpupower/utils/cpuidle-set.c
@@ -148,12 +148,21 @@ int cmd_idle_set(int argc, char **argv)
                                         (cpu, idlestate);
                                 state_latency = sysfs_get_idlestate_latency
                                         (cpu, idlestate);
-                                if (disabled == 1 || latency > state_latency)
+                                if (disabled == 1) {
+                                        if (latency > state_latency){
+                                                ret = sysfs_idlestate_disable
+                                                        (cpu, idlestate, 0);
+                                                if (ret == 0)
+                printf(_("Idlestate %u enabled on CPU %u\n"),  idlestate, cpu);
+                                        }
                                         continue;
-                                ret = sysfs_idlestate_disable
-                                        (cpu, idlestate, 1);
-                                if (ret == 0)
+                                }
+                                if (latency <= state_latency){
+                                        ret = sysfs_idlestate_disable
+                                                (cpu, idlestate, 1);
+                                        if (ret == 0)
                 printf(_("Idlestate %u disabled on CPU %u\n"), idlestate, cpu);
+                                }
                         }
                         break;
                 case 'E':