From 1ed6ba38f2b7f9161164d7fadf4245972e150c68 Mon Sep 17 00:00:00 2001
From: Jane Rachinger <jane400@bingo-ev.de>
Date: Tue, 13 Jun 2023 22:14:16 +0200
Subject: [PATCH 3/3] use relative times for broken RTCs

---
 src/main.cpp | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index f781fff..f448e88 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -34,11 +34,15 @@ std::list<Alarm> alarmList;
 sdbus::UnixFd suspendDelayLockFd;
 
 
-void writeToRTC(std::uint64_t data) {
+void writeToRTC(std::uint64_t data, bool relative) {
     std::cout << "Writing to RTC: " << data << std::endl;
     std::ofstream rtc("/sys/class/rtc/rtc0/wakealarm");
     if (rtc.is_open()) {
-        rtc << data << std::endl;
+        if (relative) {
+            rtc << "+" << data << std::endl;
+        } else {
+            rtc << data << std::endl;
+	    }
     } else {
         std::cout << "ERROR: Couldn't open RTC to write" << std::endl;
     }
@@ -69,8 +73,8 @@ void rescedule()
     if (alarmList.size()) {
         uint64_t localReadFromRTC = readFromRTC();
         if ((localReadFromRTC > alarmList.front().getTime()) || (!localReadFromRTC)) {
-            writeToRTC(0);
-            writeToRTC(alarmList.front().getTime());
+            writeToRTC(0, false);
+            writeToRTC(alarmList.front().getTime() - now, true);
         }
     }
 }
@@ -95,7 +99,7 @@ std::string removeAlarm(const std::string& id)
     if ((alarmList.size())
             && (alarmList.front().getId() == id)
             && (alarmList.front().getTime() == readFromRTC())) {
-        writeToRTC(0);
+        writeToRTC(0, false);
     }
 
     alarmList.remove_if([id](Alarm &a){return id == a.getId();});
@@ -123,7 +127,7 @@ void handleSuspend(const bool active) {
         std::time_t now = std::time(nullptr);
         if ((alarmList.size()) && (alarmList.front().getTime() < now + 10UL)) {
             std::cout << "Next alarm too close. Wake up in 10 Seconds ..." << std::endl;
-            writeToRTC(now + 10UL);
+            writeToRTC(10UL, true);
         }
         suspendDelayLockFd.reset();
     } else {
-- 
2.41.0