commit 38857578d7243fb60f2b266d291526b5b97d0fc5
author Matt Simmering <matthew.simmering@intel.com> Thu Aug 10 14:41:46 2023 -0700
committer Zhikui Ren <zhikui.ren@intel.com> Wed Aug 16 00:19:40 2023 +0000
tree 06cbe9d9553278070a9c1bc85301de036c4ff569
parent c564eda5d85d898b15c395d1e50c8989d2e4377f

intelcpusensor: Update DIMM presence check

Some Intel CPUs will use 0xFF to indicate DIMMs not being present.  Add
this check before setting dimmReady.  We should be safe checking against
0 and 0xFF since these shouldn't be actual temperatures in the field.

Also remove the check on pkgConfig[2] because bits 23:16 are reserved.

Tested: intelcpusensor doesn't set dimmReady too early in case of
Intel CPUs setting PCS 14 to 0xFFFF

Change-Id: If943736d3798d02dea17139f408572d80eb74e33
Signed-off-by: Matt Simmering <matthew.simmering@intel.com>

src/IntelCPUSensorMain.cpp

diff --git a/src/IntelCPUSensorMain.cpp b/src/IntelCPUSensorMain.cpp
index 0e0083a..ba36e41 100644
--- a/src/IntelCPUSensorMain.cpp
+++ b/src/IntelCPUSensorMain.cpp
@@ -561,8 +561,10 @@
                                      rank, 4, &pkgConfig[0],
                                      &cc) == PECI_CC_SUCCESS)
                 {
-                    if ((pkgConfig[0] != 0U) || (pkgConfig[1] != 0U) ||
-                        (pkgConfig[2] != 0U))
+                    // Depending on CPU generation, both 0 and 0xFF can be used
+                    // to indicate no DIMM presence
+                    if (((pkgConfig[0] != 0xFF) && (pkgConfig[0] != 0U)) ||
+                        ((pkgConfig[1] != 0xFF) && (pkgConfig[1] != 0U)))
                     {
                         dimmReady = true;
                         break;