commit f7f8da6fde1e2ca86f2439a2b6f55262c12c7db6
author Santosh Puranik <santosh.puranik@in.ibm.com> Fri May 06 13:01:19 2022 -0500
committer Santosh Puranik <santosh.puranik@in.ibm.com> Mon May 16 06:59:19 2022 +0000
tree a9894193f7121dba5b33b3e0f1f66b3775dc7d0d
parent f2d3b53dbf1925aded71073f2f6cff903825abcc

manager: Update BIOS Attributes only if needed

This commit adds a check before updating the FCO and AMM
BIOS attributes. If the attributes are already the value that
we are trying to update, we skip the BIOS attribute update.

This helps eliminate unnecessary BIOS updates being sent to PHYP.

Signed-off-by: Santosh Puranik <santosh.puranik@in.ibm.com>
Change-Id: Icc771a9c024cedb248a0fa2e983f9eebdc76b2b6

vpd-manager/bios_handler.cpp

diff --git a/vpd-manager/bios_handler.cpp b/vpd-manager/bios_handler.cpp
index cb251a6..2421277 100644
--- a/vpd-manager/bios_handler.cpp
+++ b/vpd-manager/bios_handler.cpp
@@ -240,13 +240,22 @@
     return ammVal;
 }
 
-void BiosHandler::saveFCOToBIOS(const std::string& fcoVal)
+void BiosHandler::saveFCOToBIOS(const std::string& fcoVal, int64_t fcoInBIOS)
 {
     if (fcoVal.size() != 4)
     {
         std::cerr << "Bad size for FCO in VPD: " << fcoVal.size() << std::endl;
         return;
     }
+
+    // Need to write?
+    if (fcoInBIOS == static_cast<int64_t>(fcoVal.at(3)))
+    {
+        std::cout << "Skip FCO BIOS write, value is already: " << fcoInBIOS
+                  << std::endl;
+        return;
+    }
+
     PendingBIOSAttrsType biosAttrs;
     biosAttrs.push_back(
         std::make_pair("hb_field_core_override",
@@ -264,7 +273,8 @@
         biosAttrs);
 }
 
-void BiosHandler::saveAMMToBIOS(const std::string& ammVal)
+void BiosHandler::saveAMMToBIOS(const std::string& ammVal,
+                                const std::string& ammInBIOS)
 {
     if (ammVal.size() != 1)
     {
@@ -279,15 +289,24 @@
                   << static_cast<int>(ammVal.at(0)) << std::endl;
         return;
     }
-    PendingBIOSAttrsType biosAttrs;
-    biosAttrs.push_back(std::make_pair(
-        "hb_memory_mirror_mode",
-        std::make_tuple("xyz.openbmc_project.BIOSConfig.Manager."
-                        "AttributeType.Enumeration",
-                        (ammVal.at(0) == 2) ? "Enabled" : "Disabled")));
 
-    std::cout << "Set hb_memory_mirror_mode to: "
-              << ((ammVal.at(0) == 2) ? "Enabled" : "Disabled") << std::endl;
+    // Need to write?
+    std::string toWrite = (ammVal.at(0) == 2) ? "Enabled" : "Disabled";
+    if (ammInBIOS == toWrite)
+    {
+        std::cout << "Skip AMM BIOS write, value is already: " << toWrite
+                  << std::endl;
+        return;
+    }
+
+    PendingBIOSAttrsType biosAttrs;
+    biosAttrs.push_back(
+        std::make_pair("hb_memory_mirror_mode",
+                       std::make_tuple("xyz.openbmc_project.BIOSConfig.Manager."
+                                       "AttributeType.Enumeration",
+                                       toWrite)));
+
+    std::cout << "Set hb_memory_mirror_mode to: " << toWrite << std::endl;
 
     setBusProperty<PendingBIOSAttrsType>(
         "xyz.openbmc_project.BIOSConfigManager",
@@ -318,7 +337,7 @@
     }
     else
     {
-        saveFCOToBIOS(fcoInVPD);
+        saveFCOToBIOS(fcoInVPD, fcoInBIOS);
     }
 
     if (ammInVPD.at(0) == 0)
@@ -327,7 +346,7 @@
     }
     else
     {
-        saveAMMToBIOS(ammInVPD);
+        saveAMMToBIOS(ammInVPD, ammInBIOS);
     }
 
     // Start listener now that we have done the restore

vpd-manager/bios_handler.hpp

diff --git a/vpd-manager/bios_handler.hpp b/vpd-manager/bios_handler.hpp
index ad6f05e..964fff5 100644
--- a/vpd-manager/bios_handler.hpp
+++ b/vpd-manager/bios_handler.hpp
@@ -115,20 +115,24 @@
     /**
      * @brief Writes Memory mirror mode to BIOS
      *
-     * Writes to the hb_memory_mirror_mode BIOS attribute.
+     * Writes to the hb_memory_mirror_mode BIOS attribute, if the value is not
+     * already the same as we are trying to write.
      *
      * @param[in] ammVal - The mirror mode as read from VPD.
+     * @param[in] ammInBIOS - The mirror more in the BIOS table.
      */
-    void saveAMMToBIOS(const std::string& ammVal);
+    void saveAMMToBIOS(const std::string& ammVal, const std::string& ammInBIOS);
 
     /**
      * @brief Writes Field Core Override to BIOS
      *
-     * Writes to the hb_field_core_override BIOS attribute.
+     * Writes to the hb_field_core_override BIOS attribute, if the value is not
+     * already the same as we are trying to write.
      *
      * @param[in] fcoVal - The FCO value as read from VPD.
+     * @param[in] fcoInBIOS - The FCO value already in the BIOS table.
      */
-    void saveFCOToBIOS(const std::string& fcoVal);
+    void saveFCOToBIOS(const std::string& fcoVal, int64_t fcoInBIOS);
 
     /**
      * @brief Reads the hb_memory_mirror_mode attribute