Apply derating factor from sensor value

    -Update getPowerLimit command to use the acutal value of
     the derating factor stored by the BMC.

Change-Id: I96d7515764569e10c54dbbbacc878514e6cf9485
RTC:124093
Reviewed-on: http://gfw160.aus.stglabs.ibm.com:8080/gerrit/18251
Tested-by: Jenkins Server
Tested-by: Jenkins OP Build CI
Reviewed-by: Brian H. Horton <brianh@linux.ibm.com>
Tested-by: Jenkins OP HW
Reviewed-by: Brian Silver <bsilver@us.ibm.com>
Reviewed-by: A. Patrick Williams III <iawillia@us.ibm.com>

1 files changed, 17 insertions, 7 deletions

diff --git a/src/usr/ipmi/ipmidcmi.C b/src/usr/ipmi/ipmidcmi.C
index 94aee18ce..c4e718b81 100644
--- a/src/usr/ipmi/ipmidcmi.C
+++ b/src/usr/ipmi/ipmidcmi.C
@@ -86,15 +86,25 @@ namespace SENSOR
                 o_powerLimit = data[5];
                 o_powerLimit = ( o_powerLimit << 8 ) + data[4];
 
-                TRACFCOMP(g_trac_ipmi,"Power limit is %d watts",o_powerLimit);
-                TRACFCOMP(g_trac_ipmi,"Power limit is %s", ((cc) ? "not active": "active"));
+                // fetch the derating factor from the BMC, then apply it to
+                // the value returned in the getPowerLimit command
+
+                SENSOR::getSensorReadingData o_sensorData;
 
-                // $TODO RTC:124093 de-rating factor for the power limit will
-                // be stored in a sensor, which is not defined currently so
-                // hardcode it at 90% efficency per power team suggestion
+                // derating factor is held in the system target
+                SENSOR::SensorBase(
+                        TARGETING::SENSOR_NAME_DERATING_FACTOR,
+                        NULL ).readSensorData( o_sensorData );
 
-                // derate the power limit to 90% of the input power
-                o_powerLimit = ( static_cast<uint32_t>(o_powerLimit) * 9 )/10;
+                // derate the power limit based on the returned value of the
+                // sensor - derating factor is returned as a % value and is
+                // stored in the event_status field.
+                o_powerLimit = ( static_cast<uint64_t>(o_powerLimit) *
+                                            o_sensorData.event_status)/100;
+
+                TRACFCOMP(g_trac_ipmi,"Derating factor = %i",o_sensorData.event_status);
+                TRACFCOMP(g_trac_ipmi,"Power limit = 0x%i",o_powerLimit);
+                TRACFCOMP(g_trac_ipmi,"Power limit is %s", ((cc) ? "not active": "active"));
 
                 // the completion code also tells us if the limit is active
                 if(l_cc == POWER_LIMIT_ACTIVE )