occ_status.cpp - openbmc/openpower-occ-control - Gitiles

 #include "occ_status.hpp"

 #include "occ_manager.hpp"
 #include "occ_sensor.hpp"
 #include "powermode.hpp"
 #include "utils.hpp"

 #include <fmt/core.h>

 #ifdef POWER10
 #include <com/ibm/Host/Target/server.hpp>
 #endif
 #include <phosphor-logging/log.hpp>

 #include <filesystem>

 namespace open_power
 {
 namespace occ
 {

 using namespace phosphor::logging;

 // Handles updates to occActive property
 bool Status::occActive(bool value)
 {
     if (value != this->occActive())
     {
         log<level::INFO>(fmt::format("Status::occActive OCC{} changed to {}",
                                      instance, value)
                              .c_str());
         if (value)
         {
             // Set the device active
             device.setActive(true);

             // Update the OCC active sensor
             Base::Status::occActive(value);

             // Start watching for errors
             addErrorWatch();

             // Reset last OCC state
             lastState = 0;

             if (device.master())
             {
                 // Update powercap bounds from OCC
                 manager.updatePcapBounds();
             }

             // Call into Manager to let know that we have bound
             if (this->managerCallBack)
             {
                 this->managerCallBack(instance, value);
             }
         }
         else
         {
 #ifdef POWER10
             if (pmode && device.master())
             {
                 // Prevent mode changes
                 pmode->setMasterActive(false);
             }
             if (safeStateDelayTimer.isEnabled())
             {
                 // stop safe delay timer
                 safeStateDelayTimer.setEnabled(false);
             }
 #endif
             // Call into Manager to let know that we will unbind.
             if (this->managerCallBack)
             {
                 this->managerCallBack(instance, value);
             }

             // Stop watching for errors
             removeErrorWatch();

             // Set the device inactive
             device.setActive(false);
         }
     }
     else if (value && !device.active())
     {
         // Existing error watch is on a dead file descriptor.
         removeErrorWatch();

         /*
          * In it's constructor, Status checks Device::bound() to see if OCC is
          * active or not.
          * Device::bound() checks for occX-dev0 directory.
          * We will lose occX-dev0 directories during FSI rescan.
          * So, if we start this application (and construct Status), and then
          * later do FSI rescan, we will end up with occActive = true and device
          * NOT bound. Lets correct that situation here.
          */
         device.setActive(true);

         // Add error watch again
         addErrorWatch();
     }
     else if (!value && device.active())
     {
         removeErrorWatch();

         // In the event that the application never receives the active signal
         // even though the OCC is active (this can occur if the BMC is rebooted
         // with the host on, since the initial OCC driver probe will discover
         // the OCCs), this application needs to be able to unbind the device
         // when we get the OCC inactive signal.
         device.setActive(false);
     }
     return Base::Status::occActive(value);
 }

 // Callback handler when a device error is reported.
 void Status::deviceError()
 {
 #ifdef POWER10
     if (pmode && device.master())
     {
         // Prevent mode changes
         pmode->setMasterActive(false);
     }
 #endif

     // This would deem OCC inactive
     this->occActive(false);

     // Reset the OCC
     this->resetOCC();
 }

 // Sends message to host control command handler to reset OCC
 void Status::resetOCC()
 {
     log<level::INFO>(
         fmt::format(">>Status::resetOCC() - requesting reset for OCC{}",
                     instance)
             .c_str());
 #ifdef PLDM
     if (resetCallBack)
     {
         this->resetCallBack(instance);
     }
 #else
     constexpr auto CONTROL_HOST_PATH = "/org/open_power/control/host0";
     constexpr auto CONTROL_HOST_INTF = "org.open_power.Control.Host";

     // This will throw exception on failure
     auto service = utils::getService(CONTROL_HOST_PATH, CONTROL_HOST_INTF);

     auto& bus = utils::getBus();
     auto method = bus.new_method_call(service.c_str(), CONTROL_HOST_PATH,
                                       CONTROL_HOST_INTF, "Execute");
     // OCC Reset control command
     method.append(convertForMessage(Control::Host::Command::OCCReset).c_str());

     // OCC Sensor ID for callout reasons
     method.append(std::variant<uint8_t>(std::get<0>(sensorMap.at(instance))));
     bus.call_noreply(method);
     return;
 #endif
 }

 // Handler called by Host control command handler to convey the
 // status of the executed command
 void Status::hostControlEvent(sdbusplus::message::message& msg)
 {
     std::string cmdCompleted{};
     std::string cmdStatus{};

     msg.read(cmdCompleted, cmdStatus);

     log<level::DEBUG>("Host control signal values",
                       entry("COMMAND=%s", cmdCompleted.c_str()),
                       entry("STATUS=%s", cmdStatus.c_str()));

     if (Control::Host::convertResultFromString(cmdStatus) !=
         Control::Host::Result::Success)
     {
         if (Control::Host::convertCommandFromString(cmdCompleted) ==
             Control::Host::Command::OCCReset)
         {
             // Must be a Timeout. Log an Error trace
             log<level::ERR>(
                 "Error resetting the OCC.", entry("PATH=%s", path.c_str()),
                 entry("SENSORID=0x%X", std::get<0>(sensorMap.at(instance))));
         }
     }
     return;
 }

 // Called from Manager::pollerTimerExpired() in preperation to POLL OCC.
 void Status::readOccState()
 {
     currentOccReadRetriesCount = occReadRetries;
     occReadStateNow();
 }

 #ifdef POWER10
 // Special processing that needs to happen once the OCCs change to ACTIVE state
 void Status::occsWentActive()
 {
     CmdStatus status = CmdStatus::SUCCESS;

     status = pmode->sendModeChange();
     if (status != CmdStatus::SUCCESS)
     {
         log<level::ERR>(
             fmt::format(
                 "Status::occsWentActive: OCC mode change failed with status {}",
                 status)
                 .c_str());

         // Disable and reset to try recovering
         deviceError();
     }

     status = pmode->sendIpsData();
     if (status != CmdStatus::SUCCESS)
     {
         log<level::ERR>(
             fmt::format(
                 "Status::occsWentActive: Sending Idle Power Save Config data failed with status {}",
                 status)
                 .c_str());

         if (status == CmdStatus::COMM_FAILURE)
         {
             // Disable and reset to try recovering
             deviceError();
         }
     }
 }

 // Send Ambient and Altitude to the OCC
 CmdStatus Status::sendAmbient(const uint8_t inTemp, const uint16_t inAltitude)
 {
     CmdStatus status = CmdStatus::FAILURE;
     bool ambientValid = true;
     uint8_t ambientTemp = inTemp;
     uint16_t altitude = inAltitude;

     if (ambientTemp == 0xFF)
     {
         // Get latest readings from manager
         manager.getAmbientData(ambientValid, ambientTemp, altitude);
         log<level::DEBUG>(
             fmt::format("sendAmbient: valid: {}, Ambient: {}C, altitude: {}m",
                         ambientValid, ambientTemp, altitude)
                 .c_str());
     }

     std::vector<std::uint8_t> cmd, rsp;
     cmd.reserve(11);
     cmd.push_back(uint8_t(CmdType::SEND_AMBIENT));
     cmd.push_back(0x00);                    // Data Length (2 bytes)
     cmd.push_back(0x08);                    //
     cmd.push_back(0x00);                    // Version
     cmd.push_back(ambientValid ? 0 : 0xFF); // Ambient Status
     cmd.push_back(ambientTemp);             // Ambient Temperature
     cmd.push_back(altitude >> 8);           // Altitude in meters (2 bytes)
     cmd.push_back(altitude & 0xFF);         //
     cmd.push_back(0x00);                    // Reserved (3 bytes)
     cmd.push_back(0x00);
     cmd.push_back(0x00);
     log<level::DEBUG>(fmt::format("sendAmbient: SEND_AMBIENT "
                                   "command to OCC{} ({} bytes)",
                                   instance, cmd.size())
                           .c_str());
     status = occCmd.send(cmd, rsp);
     if (status == CmdStatus::SUCCESS)
     {
         if (rsp.size() == 5)
         {
             if (RspStatus::SUCCESS != RspStatus(rsp[2]))
             {
                 log<level::ERR>(
                     fmt::format(
                         "sendAmbient: SEND_AMBIENT failed with rspStatus 0x{:02X}",
                         rsp[2])
                         .c_str());
                 dump_hex(rsp);
                 status = CmdStatus::FAILURE;
             }
         }
         else
         {
             log<level::ERR>(
                 fmt::format(
                     "sendAmbient: INVALID SEND_AMBIENT response length:{}",
                     rsp.size())
                     .c_str());
             dump_hex(rsp);
             status = CmdStatus::FAILURE;
         }
     }
     else
     {
         log<level::ERR>(
             fmt::format(
                 "sendAmbient: SEND_AMBIENT FAILED! with status 0x{:02X}",
                 status)
                 .c_str());

         if (status == CmdStatus::COMM_FAILURE)
         {
             // Disable and reset to try recovering
             deviceError();
         }
     }

     return status;
 }

 // Called when safe timer expires to determine if OCCs need to be reset
 void Status::safeStateDelayExpired()
 {
     if (this->occActive())
     {
         log<level::INFO>(
             fmt::format(
                 "safeStateDelayExpired: OCC{} is in SAFE state, requesting reset",
                 instance)
                 .c_str());
         // Disable and reset to try recovering
         deviceError();
     }
 }
 #endif // POWER10

 fs::path Status::getHwmonPath()
 {
     using namespace std::literals::string_literals;

     if (!fs::exists(hwmonPath))
     {
         static bool tracedFail[8] = {0};

         if (!hwmonPath.empty())
         {
             log<level::ERR>(
                 fmt::format("Status::getHwmonPath(): path no longer exists: {}",
                             hwmonPath.c_str())
                     .c_str());
             hwmonPath.clear();
         }

         // Build the base HWMON path
         fs::path prefixPath =
             fs::path{OCC_HWMON_PATH + "occ-hwmon."s +
                      std::to_string(instance + 1) + "/hwmon/"s};

         // Get the hwmonXX directory name
         try
         {
             // there should only be one directory
             const int numDirs = std::distance(
                 fs::directory_iterator(prefixPath), fs::directory_iterator{});
             if (numDirs == 1)
             {
                 hwmonPath = *fs::directory_iterator(prefixPath);
                 tracedFail[instance] = false;
             }
             else
             {
                 if (!tracedFail[instance])
                 {
                     log<level::ERR>(
                         fmt::format(
                             "Status::getHwmonPath(): Found multiple ({}) hwmon paths!",
                             numDirs)
                             .c_str());
                     tracedFail[instance] = true;
                 }
             }
         }
         catch (const fs::filesystem_error& e)
         {
             if (!tracedFail[instance])
             {
                 log<level::ERR>(
                     fmt::format(
                         "Status::getHwmonPath(): error accessing {}: {}",
                         prefixPath.c_str(), e.what())
                         .c_str());
                 tracedFail[instance] = true;
             }
         }
     }

     return hwmonPath;
 }

 // Called to read state and upon failure to read after occReadStateFailTimer.
 void Status::occReadStateNow()
 {
     unsigned int state;
     const fs::path filename =
         fs::path(DEV_PATH) /
         fs::path(sysfsName + "." + std::to_string(instance + 1)) / "occ_state";

     std::ifstream file;
     bool goodFile = false;

     // open file.
     file.open(filename, std::ios::in);
     const int openErrno = errno;

     // File is open and state can be used.
     if (file.is_open() && file.good())
     {
         goodFile = true;
         file >> state;

         if (state != lastState)
         {
             // Trace OCC state changes
             log<level::INFO>(
                 fmt::format(
                     "Status::readOccState: OCC{} state 0x{:02X} (lastState: 0x{:02X})",
                     instance, state, lastState)
                     .c_str());
             lastState = state;
 #ifdef POWER10
             if (OccState(state) == OccState::ACTIVE)
             {
                 if (pmode && device.master())
                 {
                     // Set the master OCC on the PowerMode object
                     pmode->setMasterOcc(path);
                     // Enable mode changes
                     pmode->setMasterActive();

                     // Special processing by master OCC when it goes active
                     occsWentActive();
                 }

                 CmdStatus status = sendAmbient();
                 if (status != CmdStatus::SUCCESS)
                 {
                     log<level::ERR>(
                         fmt::format(
                             "readOccState: Sending Ambient failed with status {}",
                             status)
                             .c_str());
                 }
             }

             // If OCC in known Good State.
             if ((OccState(state) == OccState::ACTIVE) ||
                 (OccState(state) == OccState::CHARACTERIZATION) ||
                 (OccState(state) == OccState::OBSERVATION))
             {
                 // Good OCC State then sensors valid again
                 stateValid = true;

                 if (safeStateDelayTimer.isEnabled())
                 {
                     // stop safe delay timer (no longer in SAFE state)
                     safeStateDelayTimer.setEnabled(false);
                 }
             }
             // Else not Valid state We would be in SAFE mode.
             // This captures both SAFE mode, and 0x00, or other invalid
             // state values.
             else
             {
                 if (!safeStateDelayTimer.isEnabled())
                 {
                     // start safe delay timer (before requesting reset)
                     using namespace std::literals::chrono_literals;
                     safeStateDelayTimer.restartOnce(60s);
                 }
                 // Not valid state, update sensors to Nan & not functional.
                 stateValid = false;
             }
 #else
             // Before P10 state not checked, only used good file open.
             stateValid = true;
 #endif
         }
     }
     file.close();

     // if failed to Read a state or not a valid state -> Attempt retry
     // after 1 Second delay if allowed.
     if ((!goodFile) || (!stateValid))
     {
         if (!goodFile)
         {
             // If not able to read, OCC may be offline
             log<level::ERR>(
                 fmt::format("Status::readOccState: open failed (errno={})",
                             openErrno)
                     .c_str());
         }
         else
         {
             // else this failed due to state not valid.
             if (state != lastState)
             {
                 log<level::ERR>(
                     fmt::format(
                         "Status::readOccState: OCC{} Invalid state 0x{:02X} (last state: 0x{:02X})",
                         instance, state, lastState)
                         .c_str());
             }
         }

 #ifdef READ_OCC_SENSORS
         manager.setSensorValueToNonFunctional(instance);
 #endif

         // See occReadRetries for number of retry attempts.
         if (currentOccReadRetriesCount > 0)
         {
             --currentOccReadRetriesCount;
 #ifdef POWER10
             using namespace std::chrono_literals;
             occReadStateFailTimer.restartOnce(1s);
 #endif
         }
         else
         {
 #ifdef POWER10
             if (!stateValid && occActive())
             {
                 if (!safeStateDelayTimer.isEnabled())
                 {
                     log<level::ERR>(
                         "Starting 60 sec delay timer before requesting a reset");
                     // start safe delay timer (before requesting reset)
                     using namespace std::literals::chrono_literals;
                     safeStateDelayTimer.restartOnce(60s);
                 }
             }
 #else
             // State could not be determined, set it to NO State.
             lastState = 0;

             // Disable the ability to send Failed actions until OCC is
             // Active again.
             stateValid = false;

             // Disable and reset to try recovering
             deviceError();
 #endif
         }
     }
 }

 } // namespace occ
 } // namespace open_power
	#include "occ_status.hpp"

	#include "occ_manager.hpp"
	#include "occ_sensor.hpp"
	#include "powermode.hpp"
	#include "utils.hpp"

	#include <fmt/core.h>

	#ifdef POWER10
	#include <com/ibm/Host/Target/server.hpp>
	#endif
	#include <phosphor-logging/log.hpp>

	#include <filesystem>

	namespace open_power
	{
	namespace occ
	{

	using namespace phosphor::logging;

	// Handles updates to occActive property
	bool Status::occActive(bool value)
	{
	if (value != this->occActive())
	{
	log<level::INFO>(fmt::format("Status::occActive OCC{} changed to {}",
	instance, value)
	.c_str());
	if (value)
	{
	// Set the device active
	device.setActive(true);

	// Update the OCC active sensor
	Base::Status::occActive(value);

	// Start watching for errors
	addErrorWatch();

	// Reset last OCC state
	lastState = 0;

	if (device.master())
	{
	// Update powercap bounds from OCC
	manager.updatePcapBounds();
	}

	// Call into Manager to let know that we have bound
	if (this->managerCallBack)
	{
	this->managerCallBack(instance, value);
	}
	}
	else
	{
	#ifdef POWER10
	if (pmode && device.master())
	{
	// Prevent mode changes
	pmode->setMasterActive(false);
	}
	if (safeStateDelayTimer.isEnabled())
	{
	// stop safe delay timer
	safeStateDelayTimer.setEnabled(false);
	}
	#endif
	// Call into Manager to let know that we will unbind.
	if (this->managerCallBack)
	{
	this->managerCallBack(instance, value);
	}

	// Stop watching for errors
	removeErrorWatch();

	// Set the device inactive
	device.setActive(false);
	}
	}
	else if (value && !device.active())
	{
	// Existing error watch is on a dead file descriptor.
	removeErrorWatch();

	/*
	* In it's constructor, Status checks Device::bound() to see if OCC is
	* active or not.
	* Device::bound() checks for occX-dev0 directory.
	* We will lose occX-dev0 directories during FSI rescan.
	* So, if we start this application (and construct Status), and then
	* later do FSI rescan, we will end up with occActive = true and device
	* NOT bound. Lets correct that situation here.
	*/
	device.setActive(true);

	// Add error watch again
	addErrorWatch();
	}
	else if (!value && device.active())
	{
	removeErrorWatch();

	// In the event that the application never receives the active signal
	// even though the OCC is active (this can occur if the BMC is rebooted
	// with the host on, since the initial OCC driver probe will discover
	// the OCCs), this application needs to be able to unbind the device
	// when we get the OCC inactive signal.
	device.setActive(false);
	}
	return Base::Status::occActive(value);
	}

	// Callback handler when a device error is reported.
	void Status::deviceError()
	{
	#ifdef POWER10
	if (pmode && device.master())
	{
	// Prevent mode changes
	pmode->setMasterActive(false);
	}
	#endif

	// This would deem OCC inactive
	this->occActive(false);

	// Reset the OCC
	this->resetOCC();
	}

	// Sends message to host control command handler to reset OCC
	void Status::resetOCC()
	{
	log<level::INFO>(
	fmt::format(">>Status::resetOCC() - requesting reset for OCC{}",
	instance)
	.c_str());
	#ifdef PLDM
	if (resetCallBack)
	{
	this->resetCallBack(instance);
	}
	#else
	constexpr auto CONTROL_HOST_PATH = "/org/open_power/control/host0";
	constexpr auto CONTROL_HOST_INTF = "org.open_power.Control.Host";

	// This will throw exception on failure
	auto service = utils::getService(CONTROL_HOST_PATH, CONTROL_HOST_INTF);

	auto& bus = utils::getBus();
	auto method = bus.new_method_call(service.c_str(), CONTROL_HOST_PATH,
	CONTROL_HOST_INTF, "Execute");
	// OCC Reset control command
	method.append(convertForMessage(Control::Host::Command::OCCReset).c_str());

	// OCC Sensor ID for callout reasons
	method.append(std::variant<uint8_t>(std::get<0>(sensorMap.at(instance))));
	bus.call_noreply(method);
	return;
	#endif
	}

	// Handler called by Host control command handler to convey the
	// status of the executed command
	void Status::hostControlEvent(sdbusplus::message::message& msg)
	{
	std::string cmdCompleted{};
	std::string cmdStatus{};

	msg.read(cmdCompleted, cmdStatus);

	log<level::DEBUG>("Host control signal values",
	entry("COMMAND=%s", cmdCompleted.c_str()),
	entry("STATUS=%s", cmdStatus.c_str()));

	if (Control::Host::convertResultFromString(cmdStatus) !=
	Control::Host::Result::Success)
	{
	if (Control::Host::convertCommandFromString(cmdCompleted) ==
	Control::Host::Command::OCCReset)
	{
	// Must be a Timeout. Log an Error trace
	log<level::ERR>(
	"Error resetting the OCC.", entry("PATH=%s", path.c_str()),
	entry("SENSORID=0x%X", std::get<0>(sensorMap.at(instance))));
	}
	}
	return;
	}

	// Called from Manager::pollerTimerExpired() in preperation to POLL OCC.
	void Status::readOccState()
	{
	currentOccReadRetriesCount = occReadRetries;
	occReadStateNow();
	}

	#ifdef POWER10
	// Special processing that needs to happen once the OCCs change to ACTIVE state
	void Status::occsWentActive()
	{
	CmdStatus status = CmdStatus::SUCCESS;

	status = pmode->sendModeChange();
	if (status != CmdStatus::SUCCESS)
	{
	log<level::ERR>(
	fmt::format(
	"Status::occsWentActive: OCC mode change failed with status {}",
	status)
	.c_str());

	// Disable and reset to try recovering
	deviceError();
	}

	status = pmode->sendIpsData();
	if (status != CmdStatus::SUCCESS)
	{
	log<level::ERR>(
	fmt::format(
	"Status::occsWentActive: Sending Idle Power Save Config data failed with status {}",
	status)
	.c_str());

	if (status == CmdStatus::COMM_FAILURE)
	{
	// Disable and reset to try recovering
	deviceError();
	}
	}
	}

	// Send Ambient and Altitude to the OCC
	CmdStatus Status::sendAmbient(const uint8_t inTemp, const uint16_t inAltitude)
	{
	CmdStatus status = CmdStatus::FAILURE;
	bool ambientValid = true;
	uint8_t ambientTemp = inTemp;
	uint16_t altitude = inAltitude;

	if (ambientTemp == 0xFF)
	{
	// Get latest readings from manager
	manager.getAmbientData(ambientValid, ambientTemp, altitude);
	log<level::DEBUG>(
	fmt::format("sendAmbient: valid: {}, Ambient: {}C, altitude: {}m",
	ambientValid, ambientTemp, altitude)
	.c_str());
	}

	std::vector<std::uint8_t> cmd, rsp;
	cmd.reserve(11);
	cmd.push_back(uint8_t(CmdType::SEND_AMBIENT));
	cmd.push_back(0x00); // Data Length (2 bytes)
	cmd.push_back(0x08); //
	cmd.push_back(0x00); // Version
	cmd.push_back(ambientValid ? 0 : 0xFF); // Ambient Status
	cmd.push_back(ambientTemp); // Ambient Temperature
	cmd.push_back(altitude >> 8); // Altitude in meters (2 bytes)
	cmd.push_back(altitude & 0xFF); //
	cmd.push_back(0x00); // Reserved (3 bytes)
	cmd.push_back(0x00);
	cmd.push_back(0x00);
	log<level::DEBUG>(fmt::format("sendAmbient: SEND_AMBIENT "
	"command to OCC{} ({} bytes)",
	instance, cmd.size())
	.c_str());
	status = occCmd.send(cmd, rsp);
	if (status == CmdStatus::SUCCESS)
	{
	if (rsp.size() == 5)
	{
	if (RspStatus::SUCCESS != RspStatus(rsp[2]))
	{
	log<level::ERR>(
	fmt::format(
	"sendAmbient: SEND_AMBIENT failed with rspStatus 0x{:02X}",
	rsp[2])
	.c_str());
	dump_hex(rsp);
	status = CmdStatus::FAILURE;
	}
	}
	else
	{
	log<level::ERR>(
	fmt::format(
	"sendAmbient: INVALID SEND_AMBIENT response length:{}",
	rsp.size())
	.c_str());
	dump_hex(rsp);
	status = CmdStatus::FAILURE;
	}
	}
	else
	{
	log<level::ERR>(
	fmt::format(
	"sendAmbient: SEND_AMBIENT FAILED! with status 0x{:02X}",
	status)
	.c_str());

	if (status == CmdStatus::COMM_FAILURE)
	{
	// Disable and reset to try recovering
	deviceError();
	}
	}

	return status;
	}

	// Called when safe timer expires to determine if OCCs need to be reset
	void Status::safeStateDelayExpired()
	{
	if (this->occActive())
	{
	log<level::INFO>(
	fmt::format(
	"safeStateDelayExpired: OCC{} is in SAFE state, requesting reset",
	instance)
	.c_str());
	// Disable and reset to try recovering
	deviceError();
	}
	}
	#endif // POWER10

	fs::path Status::getHwmonPath()
	{
	using namespace std::literals::string_literals;

	if (!fs::exists(hwmonPath))
	{
	static bool tracedFail[8] = {0};

	if (!hwmonPath.empty())
	{
	log<level::ERR>(
	fmt::format("Status::getHwmonPath(): path no longer exists: {}",
	hwmonPath.c_str())
	.c_str());
	hwmonPath.clear();
	}

	// Build the base HWMON path
	fs::path prefixPath =
	fs::path{OCC_HWMON_PATH + "occ-hwmon."s +
	std::to_string(instance + 1) + "/hwmon/"s};

	// Get the hwmonXX directory name
	try
	{
	// there should only be one directory
	const int numDirs = std::distance(
	fs::directory_iterator(prefixPath), fs::directory_iterator{});
	if (numDirs == 1)
	{
	hwmonPath = *fs::directory_iterator(prefixPath);
	tracedFail[instance] = false;
	}
	else
	{
	if (!tracedFail[instance])
	{
	log<level::ERR>(
	fmt::format(
	"Status::getHwmonPath(): Found multiple ({}) hwmon paths!",
	numDirs)
	.c_str());
	tracedFail[instance] = true;
	}
	}
	}
	catch (const fs::filesystem_error& e)
	{
	if (!tracedFail[instance])
	{
	log<level::ERR>(
	fmt::format(
	"Status::getHwmonPath(): error accessing {}: {}",
	prefixPath.c_str(), e.what())
	.c_str());
	tracedFail[instance] = true;
	}
	}
	}

	return hwmonPath;
	}

	// Called to read state and upon failure to read after occReadStateFailTimer.
	void Status::occReadStateNow()
	{
	unsigned int state;
	const fs::path filename =
	fs::path(DEV_PATH) /
	fs::path(sysfsName + "." + std::to_string(instance + 1)) / "occ_state";

	std::ifstream file;
	bool goodFile = false;

	// open file.
	file.open(filename, std::ios::in);
	const int openErrno = errno;

	// File is open and state can be used.
	if (file.is_open() && file.good())
	{
	goodFile = true;
	file >> state;

	if (state != lastState)
	{
	// Trace OCC state changes
	log<level::INFO>(
	fmt::format(
	"Status::readOccState: OCC{} state 0x{:02X} (lastState: 0x{:02X})",
	instance, state, lastState)
	.c_str());
	lastState = state;
	#ifdef POWER10
	if (OccState(state) == OccState::ACTIVE)
	{
	if (pmode && device.master())
	{
	// Set the master OCC on the PowerMode object
	pmode->setMasterOcc(path);
	// Enable mode changes
	pmode->setMasterActive();

	// Special processing by master OCC when it goes active
	occsWentActive();
	}

	CmdStatus status = sendAmbient();
	if (status != CmdStatus::SUCCESS)
	{
	log<level::ERR>(
	fmt::format(
	"readOccState: Sending Ambient failed with status {}",
	status)
	.c_str());
	}
	}

	// If OCC in known Good State.
	if ((OccState(state) == OccState::ACTIVE) \|\|
	(OccState(state) == OccState::CHARACTERIZATION) \|\|
	(OccState(state) == OccState::OBSERVATION))
	{
	// Good OCC State then sensors valid again
	stateValid = true;

	if (safeStateDelayTimer.isEnabled())
	{
	// stop safe delay timer (no longer in SAFE state)
	safeStateDelayTimer.setEnabled(false);
	}
	}
	// Else not Valid state We would be in SAFE mode.
	// This captures both SAFE mode, and 0x00, or other invalid
	// state values.
	else
	{
	if (!safeStateDelayTimer.isEnabled())
	{
	// start safe delay timer (before requesting reset)
	using namespace std::literals::chrono_literals;
	safeStateDelayTimer.restartOnce(60s);
	}
	// Not valid state, update sensors to Nan & not functional.
	stateValid = false;
	}
	#else
	// Before P10 state not checked, only used good file open.
	stateValid = true;
	#endif
	}
	}
	file.close();

	// if failed to Read a state or not a valid state -> Attempt retry
	// after 1 Second delay if allowed.
	if ((!goodFile) \|\| (!stateValid))
	{
	if (!goodFile)
	{
	// If not able to read, OCC may be offline
	log<level::ERR>(
	fmt::format("Status::readOccState: open failed (errno={})",
	openErrno)
	.c_str());
	}
	else
	{
	// else this failed due to state not valid.
	if (state != lastState)
	{
	log<level::ERR>(
	fmt::format(
	"Status::readOccState: OCC{} Invalid state 0x{:02X} (last state: 0x{:02X})",
	instance, state, lastState)
	.c_str());
	}
	}

	#ifdef READ_OCC_SENSORS
	manager.setSensorValueToNonFunctional(instance);
	#endif

	// See occReadRetries for number of retry attempts.
	if (currentOccReadRetriesCount > 0)
	{
	--currentOccReadRetriesCount;
	#ifdef POWER10
	using namespace std::chrono_literals;
	occReadStateFailTimer.restartOnce(1s);
	#endif
	}
	else
	{
	#ifdef POWER10
	if (!stateValid && occActive())
	{
	if (!safeStateDelayTimer.isEnabled())
	{
	log<level::ERR>(
	"Starting 60 sec delay timer before requesting a reset");
	// start safe delay timer (before requesting reset)
	using namespace std::literals::chrono_literals;
	safeStateDelayTimer.restartOnce(60s);
	}
	}
	#else
	// State could not be determined, set it to NO State.
	lastState = 0;

	// Disable the ability to send Failed actions until OCC is
	// Active again.
	stateValid = false;

	// Disable and reset to try recovering
	deviceError();
	#endif
	}
	}
	}

	} // namespace occ
	} // namespace open_power