Merge pull request 'add a way to detect off or broken SUS devices' (#587) from bugfix_sus_fdir into develop

Reviewed-on: #587
Reviewed-by: Marius Eggert <eggertm@irs.uni-stuttgart.de>

CHANGELOG.md

@@ -22,6 +22,8 @@ will consitute of a breaking change warranting a new major release:
   to a regression, so commanding the SDC state machine externally lead to confusing results.
 - Fixed a bug in persistent TM store, where the active file was not reset of SD card switches.
   SD card switch from 0 to 1 and vice-versa works without errors from persistent TM stores now.
+- Add a way for the SUS polling to detect broken or off devices by checking the retrieved
+  temperature for the all-ones value (0x0fff).
 
 ## Changed
 

linux/acs/SusPolling.cpp

@@ -73,6 +73,7 @@ ReturnValue_t SusPolling::sendMessage(CookieIF* cookie, const uint8_t* sendData,
       susDevs[susIdx].ownReply.cfgWasSet = false;
       susDevs[susIdx].ownReply.dataWasSet = false;
     }
+    susDevs[susIdx].replyResult = returnvalue::FAILED;
     susDevs[susIdx].mode = susReq->mode;
   }
   if (state == InternalState::IDLE) {
@@ -95,11 +96,14 @@ ReturnValue_t SusPolling::readReceivedMessage(CookieIF* cookie, uint8_t** buffer
   if (susIdx < 0) {
     return FAILED;
   }
+  if(susDevs[susIdx].replyResult != returnvalue::OK) {
+    return susDevs[susIdx].replyResult;
+  }
   MutexGuard mg(ipcLock);
   std::memcpy(&susDevs[susIdx].readerReply, &susDevs[susIdx].ownReply, sizeof(acs::SusReply));
   *buffer = reinterpret_cast<uint8_t*>(&susDevs[susIdx].readerReply);
   *size = sizeof(acs::SusReply);
-  return OK;
+  return susDevs[susIdx].replyResult;
 }
 
 ReturnValue_t SusPolling::handleSusPolling() {
@@ -164,6 +168,12 @@ ReturnValue_t SusPolling::handleSusPolling() {
       }
       MutexGuard mg(ipcLock);
       susDevs[idx].ownReply.tempRaw = ((rawReply[0] & 0x0f) << 8) | rawReply[1];
+      // Reply is all ones. Sensor is probably off or faulty when
+      // it should not be.
+      if(susDevs[idx].ownReply.tempRaw == 0x0fff) {
+        susDevs[idx].replyResult = returnvalue::FAILED;
+      } else {
+        susDevs[idx].replyResult = returnvalue::OK;
         for (unsigned chIdx = 0; chIdx < 6; chIdx++) {
           susDevs[idx].ownReply.channelsRaw[chIdx] =
               (rawReply[chIdx * 2 + 2] << 8) | rawReply[chIdx * 2 + 3];
@@ -171,6 +181,7 @@ ReturnValue_t SusPolling::handleSusPolling() {
         susDevs[idx].ownReply.dataWasSet = true;
       }
     }
+  }
   return OK;
 }