From 9a72f1c6a2d903a5691c39d47f30bd86202655e2 Mon Sep 17 00:00:00 2001
From: Jacob Scheiffler <86001820+Jacob-Scheiffler@users.noreply.github.com>
Date: Thu, 12 Oct 2023 13:15:44 -0500
Subject: [PATCH] fix(PeriphDrivers): MSDK-1242: Fix false stop detection in
 I2C interrupt handler (#765)

---
 Libraries/PeriphDrivers/Source/I2C/i2c_reva.c | 48 +++++++++++--------
 1 file changed, 27 insertions(+), 21 deletions(-)

diff --git a/Libraries/PeriphDrivers/Source/I2C/i2c_reva.c b/Libraries/PeriphDrivers/Source/I2C/i2c_reva.c
index 55554a788b..c9b3d0c615 100644
--- a/Libraries/PeriphDrivers/Source/I2C/i2c_reva.c
+++ b/Libraries/PeriphDrivers/Source/I2C/i2c_reva.c
@@ -1531,9 +1531,36 @@ void MXC_I2C_RevA_SlaveAsyncHandler(mxc_i2c_reva_regs_t *i2c, mxc_i2c_reva_slave
         }
     }
 
+    // Check if transaction completed or restart occurred
+    if (int_en[0] & MXC_F_I2C_REVA_INTFL0_DONE) {
+        if (tFlags & MXC_F_I2C_REVA_INTFL0_STOP) {
+            // Stop/NACK condition occurred, transaction complete
+            *retVal = E_NO_ERROR;
+
+            if (callback != NULL) {
+                callback(i2c, MXC_I2C_REVA_EVT_TRANS_COMP, retVal);
+            }
+
+            i2c->intfl0 = MXC_F_I2C_REVA_INTFL0_STOP;
+            int_en[0] = 0;
+            int_en[1] = 0;
+            AsyncRequests[MXC_I2C_GET_IDX((mxc_i2c_regs_t *)i2c)] = NULL;
+        } else if (tFlags & MXC_F_I2C_REVA_INTFL0_DONE) {
+            // Restart detected, re-arm address match interrupt
+            i2c->intfl0 = MXC_F_I2C_REVA_INTFL0_DONE;
+            int_en[0] = MXC_F_I2C_REVA_INTFL0_ADDR_MATCH;
+        }
+    }
+
     // Check for address match interrupt
     if (int_en[0] & MXC_F_I2C_REVA_INTFL0_ADDR_MATCH) {
         if (tFlags & MXC_F_I2C_REVA_INTFL0_ADDR_MATCH) {
+            // Address match occurred, prepare for transaction
+            if (tFlags & MXC_F_I2C_REVA_INTFL0_STOP && !(tFlags & MXC_F_I2C_REVA_INTFL0_DONE)) {
+                // Clear stop flag if it was asserted in a previous transaction
+                i2c->intfl0 = MXC_F_I2C_REVA_INTFL0_STOP;
+            }
+
             if (i2c->ctrl & MXC_F_I2C_REVA_CTRL_READ) {
                 // Read request received from the master
                 if (callback != NULL) {
@@ -1561,27 +1588,6 @@ void MXC_I2C_RevA_SlaveAsyncHandler(mxc_i2c_reva_regs_t *i2c, mxc_i2c_reva_slave
             }
         }
     }
-
-    // Check if transaction completed or restart occurred
-    if (int_en[0] & MXC_F_I2C_REVA_INTFL0_DONE) {
-        if (tFlags & MXC_F_I2C_REVA_INTFL0_STOP) {
-            // Stop/NACK condition occurred, transaction complete
-            *retVal = E_NO_ERROR;
-
-            if (callback != NULL) {
-                callback(i2c, MXC_I2C_REVA_EVT_TRANS_COMP, retVal);
-            }
-
-            i2c->intfl0 = MXC_F_I2C_REVA_INTFL0_STOP;
-            int_en[0] = 0;
-            int_en[1] = 0;
-            AsyncRequests[MXC_I2C_GET_IDX((mxc_i2c_regs_t *)i2c)] = NULL;
-        } else if (tFlags & MXC_F_I2C_REVA_INTFL0_DONE) {
-            // Restart detected, re-arm address match interrupt
-            i2c->intfl0 = MXC_F_I2C_REVA_INTFL0_DONE;
-            int_en[0] = MXC_F_I2C_REVA_INTFL0_ADDR_MATCH;
-        }
-    }
 }
 
 void MXC_I2C_RevA_AsyncHandler(mxc_i2c_reva_regs_t *i2c, uint32_t interruptCheck)