pid/fancontroller: Set failsafe PWM in destructor
Introduce a new feature that's guarded by a new meson option
'offline-failsafe-pwm':
After the FanController object was destroyed it can no longer regulate
the fans. To prevent system failure set all fans to the FailSafePercent
defined in the configuration.
In addition to rebuilding configuration it also allows to keep the fans
in FailSafe mode as long as the phosphor-pid-control.service is stopped
or the system reboots. However this change doesn't cover the case of
a program crash where the destructor won't be executed. Abnormal program
termination must be handled by systemd and it out of scope of this
change.
Tested: 'systemctl stop phosphor-pid-control.service' and see the fans
ramp up to FailSafePercent.
Change-Id: I81262b07fd4c1212efc1a4ba4635bde8bc7b5215
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
diff --git a/configure.md b/configure.md
index 164e2e3..02752ca 100644
--- a/configure.md
+++ b/configure.md
@@ -23,6 +23,12 @@
this enabled, the PWM is calculated and set to the calculated PWM **or** the
failsafe PWM, whichever is higher.
+### --offline-failsafe-pwm
+
+This build flag is used to set the fans to failsafe percent when offline. The
+controller is offline when it's rebuilding the configuration or when it's about
+to shutdown.
+
## JSON Configuration
Default config file path `/usr/share/swampd/config.json` can be overridden by
diff --git a/meson.build b/meson.build
index 552634e..967087a 100644
--- a/meson.build
+++ b/meson.build
@@ -17,6 +17,7 @@
conf_data.set('BINDIR', bindir)
conf_data.set('SYSTEMD_TARGET', get_option('systemd_target'))
conf_data.set('STRICT_FAILSAFE_PWM', get_option('strict-failsafe-pwm'))
+conf_data.set('OFFLINE_FAILSAFE_PWM', get_option('offline-failsafe-pwm'))
configure_file(output: 'config.h',
configuration: conf_data
diff --git a/meson.options b/meson.options
index 9205b1b..fc65cdb 100644
--- a/meson.options
+++ b/meson.options
@@ -1,4 +1,5 @@
option('tests', type: 'feature', value: 'enabled', description: 'Build tests')
option('oe-sdk', type: 'feature', value: 'disabled', description: 'Enable OE SDK')
option('strict-failsafe-pwm', type: 'boolean', value: false, description: 'Set the fans strictly at the failsafe PWM when in failsafe mode')
+option('offline-failsafe-pwm', type: 'boolean', value: false, description: 'Set the fans at the failsafe PWM when reloading or terminated.')
option('systemd_target', type: 'string', value: 'multi-user.target', description: 'Target for starting this service')
diff --git a/pid/fancontroller.cpp b/pid/fancontroller.cpp
index 8bbe3f2..b0591b5 100644
--- a/pid/fancontroller.cpp
+++ b/pid/fancontroller.cpp
@@ -212,4 +212,34 @@
return;
}
+FanController::~FanController()
+{
+#ifdef OFFLINE_FAILSAFE_PWM
+ double percent = _owner->getFailSafePercent();
+ if (debugEnabled)
+ {
+ std::cerr << "Zone " << _owner->getZoneID()
+ << " offline fans output pwm: " << percent << "\n";
+ }
+
+ // value and kFanFailSafeDutyCycle are 10 for 10% so let's fix that.
+ percent /= 100.0;
+
+ // PidSensorMap for writing.
+ for (const auto& it : _inputs)
+ {
+ auto sensor = _owner->getSensor(it);
+ auto redundantWrite = _owner->getRedundantWrite();
+ int64_t rawWritten;
+ sensor->write(percent, redundantWrite, &rawWritten);
+
+ // The outputCache will be used later,
+ // to store a record of the PWM commanded,
+ // so that this information can be included during logging.
+ auto unscaledWritten = static_cast<double>(rawWritten);
+ _owner->setOutputCache(sensor->getName(), {percent, unscaledWritten});
+ }
+#endif
+}
+
} // namespace pid_control
diff --git a/pid/fancontroller.hpp b/pid/fancontroller.hpp
index 447ce7b..c2b76b9 100644
--- a/pid/fancontroller.hpp
+++ b/pid/fancontroller.hpp
@@ -29,7 +29,7 @@
PIDController(id, owner),
_inputs(inputs), _direction(FanSpeedDirection::NEUTRAL)
{}
-
+ ~FanController();
double inputProc(void) override;
double setptProc(void) override;
void outputProc(double value) override;