From d466dc8421ee0c6592bb5682aa93a671bc948107 Mon Sep 17 00:00:00 2001
From: Chamira Perera <chamira.perera@audinate.com>
Date: Thu, 15 Jun 2023 14:03:05 +1000
Subject: [PATCH] stm32cube: stm32h7: use transmit timestamp status flag.

Read timestamp only when status flag is set in Tx descriptor.
Fire transmit timestamp callbacks only when there is a valid
non-zero timestamp.

Co-authored-by: Naeem Bacha <naeem.bacha@audinate.com>
Signed-off-by: Chamira Perera <chamira.perera@audinate.com>
---
 stm32cube/stm32h7xx/README                    |  8 ++++++
 .../stm32h7xx/drivers/src/stm32h7xx_hal_eth.c | 27 ++++++++++++++-----
 2 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/stm32cube/stm32h7xx/README b/stm32cube/stm32h7xx/README
index 98e55a1a6..6e90026dc 100644
--- a/stm32cube/stm32h7xx/README
+++ b/stm32cube/stm32h7xx/README
@@ -68,4 +68,12 @@ Patch List:
       drivers/include/stm32h7xx_hal_def.h
      ST Internal Reference: 136825
 
+   *Fix to use transmit timestamp when it is valid
+    Read timestamp only when status flag is set in Tx descriptor.
+    Fire transmit timestamp callbacks only when there is a valid
+    non-zero timestamp.
+    Impacted files:
+     drivers/src/stm32h7xx_hal_eth.c
+    ST Internal Reference: 157129
+
    See release_note.html from STM32Cube
diff --git a/stm32cube/stm32h7xx/drivers/src/stm32h7xx_hal_eth.c b/stm32cube/stm32h7xx/drivers/src/stm32h7xx_hal_eth.c
index 4850fb569..7a7f80032 100644
--- a/stm32cube/stm32h7xx/drivers/src/stm32h7xx_hal_eth.c
+++ b/stm32cube/stm32h7xx/drivers/src/stm32h7xx_hal_eth.c
@@ -1432,17 +1432,29 @@ HAL_StatusTypeDef HAL_ETH_ReleaseTxPacket(ETH_HandleTypeDef *heth)
         /* Disable Ptp transmission */
         CLEAR_BIT(heth->Init.TxDesc[idx].DESC3, (0x40000000U));
 
-        /* Get timestamp low */
-        timestamp->TimeStampLow = heth->Init.TxDesc[idx].DESC0;
-        /* Get timestamp high */
-        timestamp->TimeStampHigh = heth->Init.TxDesc[idx].DESC1;
+        if ((heth->Init.TxDesc[idx].DESC3 & ETH_DMATXNDESCWBF_LD )
+          && (heth->Init.TxDesc[idx].DESC3 & ETH_DMATXNDESCWBF_TTSS))
+        {
+          /* Get timestamp low */
+          timestamp->TimeStampLow = heth->Init.TxDesc[idx].DESC0;
+          /* Get timestamp high */
+          timestamp->TimeStampHigh = heth->Init.TxDesc[idx].DESC1;
+        }
+        else
+        {
+          timestamp->TimeStampHigh = timestamp->TimeStampLow = UINT32_MAX;
+        }
+
 #endif /* HAL_ETH_USE_PTP */
 
 #if (USE_HAL_ETH_REGISTER_CALLBACKS == 1)
         /*Call registered callbacks*/
 #ifdef HAL_ETH_USE_PTP
         /* Handle Ptp  */
-        heth->txPtpCallback(dmatxdesclist->PacketAddress[idx], timestamp);
+        if (timestamp->TimeStampHigh != UINT32_MAX && timestamp->TimeStampLow != UINT32_MAX)
+        {
+          heth->txPtpCallback(dmatxdesclist->PacketAddress[idx], timestamp);
+        }
 #endif  /* HAL_ETH_USE_PTP */
         /* Release the packet.  */
         heth->txFreeCallback(dmatxdesclist->PacketAddress[idx]);
@@ -1450,7 +1462,10 @@ HAL_StatusTypeDef HAL_ETH_ReleaseTxPacket(ETH_HandleTypeDef *heth)
         /* Call callbacks */
 #ifdef HAL_ETH_USE_PTP
         /* Handle Ptp  */
-        HAL_ETH_TxPtpCallback(dmatxdesclist->PacketAddress[idx], timestamp);
+        if (timestamp->TimeStampHigh != UINT32_MAX && timestamp->TimeStampLow != UINT32_MAX)
+        {
+          HAL_ETH_TxPtpCallback(dmatxdesclist->PacketAddress[idx], timestamp);
+        }
 #endif  /* HAL_ETH_USE_PTP */
         /* Release the packet.  */
         HAL_ETH_TxFreeCallback(dmatxdesclist->PacketAddress[idx]);