commit 572f823ced036674ee4ee528c94ce0c1d98c80d4
author Thierry Strudel <tstrudel@google.com> Mon Jun 18 15:01:57 2018 -0700
committer Thierry Strudel <tstrudel@google.com> Thu Jun 21 08:12:39 2018 +0000
tree 688a8cf26fdeb114ff1874efb160c81c9b67358c
parent e04a138a0123952e05a46505eddb4b2f7adf3b96

health: fix learned capacity backup/restore

The code was only allowing the Learned Capacity to decrease while
QCOM FG learned capacity may actually go up for some reasons.
Ensure we use the FG learned capacity on update and always restore
the saved one on boot.

Bug: 109734601
Change-Id: I13ff3f662e423fda59779b8c9a491956ebd65c5a
Signed-off-by: Thierry Strudel <tstrudel@google.com>

health/LearnedCapacityBackupRestore.cpp

diff --git a/health/LearnedCapacityBackupRestore.cpp b/health/LearnedCapacityBackupRestore.cpp
index f34b909..bf72526 100644
--- a/health/LearnedCapacityBackupRestore.cpp
+++ b/health/LearnedCapacityBackupRestore.cpp
@@ -25,17 +25,28 @@
 static constexpr char kSysCFPersistFile[] = "/persist/battery/qcom_charge_full";
 static constexpr int kBuffSize = 256;
 
-LearnedCapacityBackupRestore::LearnedCapacityBackupRestore() {}
+LearnedCapacityBackupRestore::LearnedCapacityBackupRestore() : sw_cap_(0), hw_cap_(0) {}
 
 void LearnedCapacityBackupRestore::Restore() {
     ReadFromStorage();
     ReadFromSRAM();
-    UpdateAndSave();
+    if (sw_cap_ == 0) {
+        // First backup
+        sw_cap_ = hw_cap_;
+        SaveToStorage();
+    } else {
+        // Always restore backup value
+        SaveToSRAM();
+    }
 }
 
 void LearnedCapacityBackupRestore::Backup() {
     ReadFromSRAM();
-    UpdateAndSave();
+    if (sw_cap_ != hw_cap_) {
+        // Always backup the new FG computed learned capacity
+        sw_cap_ = hw_cap_;
+        SaveToStorage();
+    }
 }
 
 void LearnedCapacityBackupRestore::ReadFromStorage() {
@@ -90,24 +101,6 @@
         LOG(ERROR) << "Write data error: " << strerror(errno);
 }
 
-void LearnedCapacityBackupRestore::UpdateAndSave() {
-    bool backup = false;
-    bool restore = false;
-    if (hw_cap_) {
-        if ((hw_cap_ < sw_cap_) || (sw_cap_ == 0)) {
-            sw_cap_ = hw_cap_;
-            backup = true;
-        } else if (hw_cap_ > sw_cap_) {
-            hw_cap_ = sw_cap_;
-            restore = true;
-        }
-    }
-    if (restore)
-        SaveToSRAM();
-    if (backup)
-        SaveToStorage();
-}
-
 }  // namespace health
 }  // namespace marlin
 }  // namespace google

health/LearnedCapacityBackupRestore.h

diff --git a/health/LearnedCapacityBackupRestore.h b/health/LearnedCapacityBackupRestore.h
index 4e40ab5..8b52343 100644
--- a/health/LearnedCapacityBackupRestore.h
+++ b/health/LearnedCapacityBackupRestore.h
@@ -41,7 +41,6 @@
     void SaveToStorage();
     void ReadFromSRAM();
     void SaveToSRAM();
-    void UpdateAndSave();
 };
 
 }  // namespace health