From 16ea60a4fb84eedeb7532aff0669342eb03bfb87 Mon Sep 17 00:00:00 2001
From: Ville Granroth <ville.granroth@gmail.com>
Date: Tue, 13 Aug 2024 07:35:18 +0300
Subject: [PATCH] add caching, minor improvements

---
 fancontrol.pl | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/fancontrol.pl b/fancontrol.pl
index d61c808..b17ae9f 100755
--- a/fancontrol.pl
+++ b/fancontrol.pl
@@ -16,10 +16,14 @@ use List::Util qw[min max];
 `ipmitool sensor thresh FAN4 lower 0 100 200`;
 `ipmitool sensor thresh FAN5 lower 0 100 200`;
 
+# cache SDR data for faster access
+`rm /opt/ipmi-cache.sdr`;
+`while ipmitool sdr dump /opt/ipmi-cache.sdr; [ $? != 0 ]; do sleep 2; done`;
+
 my $min_temp_change     = 2; # °C minimum change to actually cause a fan speed update
 my $seconds_to_sleep    = 2; # Number of seconds to sleep between update loops
 
-# 0x64 = 100, 0x00 = 0. 
+# 0x64 = 100, 0x00 = 0.
 # CPU Temp -> Fan Speed Mappings
 my %cpu_temp_to_fan_speed;
    $cpu_temp_to_fan_speed{80} = 0x64;
@@ -53,9 +57,9 @@ my $g_current_cpu_temp = 0;
 my $g_last_set_cpu_temp = 0;
 my $g_last_set_sys_temp = 0;
 
-sub UpdateFanSpeed { 
-  # Gather statistics for fan speed and CPU Temp and stuch
-  my $ipmi_output = `ipmitool sdr list full`;
+sub UpdateFanSpeed {
+  # Gather statistics for fan speed and CPU Temp
+  my $ipmi_output = `ipmitool sdr list full -S /opt/ipmi-cache.sdr`;
   my @vals = split( "\n", $ipmi_output );
 
   my $current_cpu_temp = 0;
@@ -74,7 +78,7 @@ sub UpdateFanSpeed {
       my      $sys_temp = $2;
       $current_sys_temp = max( $sys_temp, $current_sys_temp );
     }
-    
+
   } # foreach my $value (@vals)
 
   $g_current_cpu_temp = $current_cpu_temp;
@@ -82,7 +86,7 @@ sub UpdateFanSpeed {
 
   my $desired_cpu_fan_speed = 0x0;
   my $desired_sys_fan_speed = 0x0;
- 
+
   my @cpu_temps = keys %cpu_temp_to_fan_speed;
   for my $cpu_temp (@cpu_temps) {
     if( $current_cpu_temp >= $cpu_temp ) {
@@ -102,16 +106,16 @@ sub UpdateFanSpeed {
       # print "The fan speed setting for GPU Temp $sys_temp *C is $sys_temp_to_fan_speed{$sys_temp} % duty cycle\n";
     }
   }
-  
+
   if( $desired_cpu_fan_speed == 0x0 ) {
     print "\n***** ERROR: Failed to determine a desired fan speed. Forcing CPU fans to 100% duty cycle as a safety fallback measure. *****\n";
     $desired_cpu_fan_speed = 0x64;
-  } 
+  }
 
   if( $desired_sys_fan_speed == 0x0 ) {
     print "\n***** ERROR: Failed to determine a desired fan speed. Forcing SYS fans to 100% duty cycle as a safety fallback measure. *****\n";
     $desired_sys_fan_speed = 0x64;
-  }  
+  }
 
   $cpu_temp_difference = $g_current_cpu_temp - $g_last_set_cpu_temp;
   $sys_temp_difference = $g_current_sys_temp - $g_last_set_sys_temp;
@@ -132,7 +136,7 @@ sub UpdateFanSpeed {
     $g_current_cpu_fan_duty_cycle = $desired_cpu_fan_speed;
 
     `ipmitool raw 0x30 0x70 0x66 0x01 0x00 $desired_cpu_fan_speed`;
-  }  
+  }
 
 }
 
@@ -144,4 +148,4 @@ while( 1 ) {
   UpdateFanSpeed();
   #print "Update Complete - going to sleep for $seconds_to_sleep seconds...\n";
   sleep $seconds_to_sleep;
-}
+}
\ No newline at end of file