From 25da1316535cdc053ee96bc2036e5a082f50ccfe Mon Sep 17 00:00:00 2001
From: Robin Mueller <robin.mueller.m@gmail.com>
Date: Thu, 29 Jun 2023 00:33:58 +0200
Subject: [PATCH] seems to work well

---
 linux/ipcore/PapbVcInterface.cpp | 27 ++++++++++++++++++++++++++-
 linux/ipcore/PapbVcInterface.h   |  3 +++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/linux/ipcore/PapbVcInterface.cpp b/linux/ipcore/PapbVcInterface.cpp
index 98cb1b41..5dcb4519 100644
--- a/linux/ipcore/PapbVcInterface.cpp
+++ b/linux/ipcore/PapbVcInterface.cpp
@@ -33,9 +33,21 @@ ReturnValue_t PapbVcInterface::write(const uint8_t* data, size_t size) {
   } else {
     return DirectTmSinkIF::IS_BUSY;
   }
+  if (not pollReadyForOctet(MAX_BUSY_POLLS)) {
+    abortPacketTransfer();
+    return returnvalue::FAILED;
+  }
   for (size_t idx = 0; idx < size; idx++) {
+    if (not pollReadyForOctet(MAX_BUSY_POLLS)) {
+      abortPacketTransfer();
+      return returnvalue::FAILED;
+    }
     *(vcBaseReg + DATA_REG_OFFSET) = static_cast<uint32_t>(data[idx]);
   }
+  if (not pollReadyForOctet(MAX_BUSY_POLLS)) {
+    abortPacketTransfer();
+    return returnvalue::FAILED;
+  }
   completePacketTransfer();
   return returnvalue::OK;
 }
@@ -50,7 +62,6 @@ bool PapbVcInterface::pollReadyForPacket() const {
   //  Check if PAPB interface is ready to receive data. Use the configuration register for this.
   //  Bit 5, see PTME ptme_001_01-0-7-r2 Table 31.
   uint32_t reg = *vcBaseReg;
-  // bool busy = (reg >> 5) & 0b1;
   return (reg >> 6) & 0b1;
 }
 
@@ -76,6 +87,20 @@ bool PapbVcInterface::isBusy() const { return not pollReadyForPacket(); }
 
 void PapbVcInterface::cancelTransfer() { abortPacketTransfer(); }
 
+inline bool PapbVcInterface::pollReadyForOctet(uint32_t maxCycles) const {
+  uint32_t reg;
+  uint32_t idx = 0;
+  while (idx < maxCycles) {
+    reg = *vcBaseReg;
+    // Busy bit.
+    if (not((reg >> 5) & 0b1)) {
+      return true;
+    }
+    idx++;
+  }
+  return false;
+}
+
 ReturnValue_t PapbVcInterface::sendTestFrame() {
   /** Size of one complete transfer frame data field amounts to 1105 bytes */
   uint8_t testPacket[1105];
diff --git a/linux/ipcore/PapbVcInterface.h b/linux/ipcore/PapbVcInterface.h
index ba6063b5..9c6734e8 100644
--- a/linux/ipcore/PapbVcInterface.h
+++ b/linux/ipcore/PapbVcInterface.h
@@ -80,6 +80,7 @@ class PapbVcInterface : public VirtualChannelIF {
 
   static constexpr long int FIRST_DELAY_PAPB_POLLING_NS = 10;
   static constexpr long int MAX_DELAY_PAPB_POLLING_NS = 40;
+  static constexpr uint32_t MAX_BUSY_POLLS = 100000;
 
   LinuxLibgpioIF* gpioComIF = nullptr;
   /** High when external buffer memory of virtual channel is empty */
@@ -118,6 +119,8 @@ class PapbVcInterface : public VirtualChannelIF {
    */
   inline bool pollReadyForPacket() const;
 
+  inline bool pollReadyForOctet(uint32_t maxCycles) const;
+
   /**
    * @brief   This function can be used for debugging to check whether there are packets in
    *          the packet buffer of the virtual channel or not.