From 388f0dce16f9847e8a9368569639f4c60c1bf3be Mon Sep 17 00:00:00 2001
From: Evan Lojewski <github@meklort.com>
Date: Sun, 13 Jun 2021 20:04:55 -0600
Subject: ape: Fix a possible race condition where MII contention could exist.
 (#220)

This ensure the APE locks the MII interface before accessing it to avoid collisions with the host.
---
 libs/Network/include/Network.h |  1 +
 libs/Network/ports.c           | 21 +++++++++++++--------
 2 files changed, 14 insertions(+), 8 deletions(-)

(limited to 'libs')

diff --git a/libs/Network/include/Network.h b/libs/Network/include/Network.h
index ec57a17..dadc2e8 100644
--- a/libs/Network/include/Network.h
+++ b/libs/Network/include/Network.h
@@ -112,6 +112,7 @@ void Network_resetRX(NetworkPort_t *port, reload_type_t reset_phy);
 void Network_checkPortState(NetworkPort_t *port);
 bool Network_updatePortState(NetworkPort_t *port);
 bool Network_checkEnableState(NetworkPort_t *port);
+void Network_setEnableState(NetworkPort_t *port);
 
 bool Network_isLinkUp(NetworkPort_t *port);
 void Network_resetLink(NetworkPort_t *port);
diff --git a/libs/Network/ports.c b/libs/Network/ports.c
index 92391f5..cde3f18 100644
--- a/libs/Network/ports.c
+++ b/libs/Network/ports.c
@@ -863,6 +863,12 @@ bool Network_checkEnableState(NetworkPort_t *port)
     return true;
 }
 
+void Network_setEnableState(NetworkPort_t *port)
+{
+    APE.Mode.r32 |= port->APEModeEnable.r32;
+    APE.Mode2.r32 |= port->APEMode2Enable.r32;
+}
+
 void Network_InitPort(NetworkPort_t *port, reload_type_t reset_phy)
 {
     RegMIIStatus_t stat;
@@ -870,20 +876,18 @@ void Network_InitPort(NetworkPort_t *port, reload_type_t reset_phy)
     RegSHM_CHANNELNcsiChannelStatus_t linkStatus;
     uint8_t phy = MII_getPhy(port->device);
 
+    APE_aquireLock();
+
     if ((ALWAYS_RESET == reset_phy) || (AS_NEEDED == reset_phy && !Network_isLinkUp(port)))
     {
-        APE_aquireLock();
         MII_reset(port->device, phy);
-        APE_releaseLock();
     }
     else
     {
         bool updated;
 
         // Ensure the PHY is advertising all capabilities and updating if needed.
-        APE_aquireLock();
         updated = MII_UpdateAdvertisement(port->device, phy);
-        APE_releaseLock();
 
         if (updated)
         {
@@ -900,8 +904,7 @@ void Network_InitPort(NetworkPort_t *port, reload_type_t reset_phy)
     Network_resetTX(port, reset_phy);
     Network_resetRX(port, reset_phy);
 
-    APE.Mode.r32 |= port->APEModeEnable.r32;
-    APE.Mode2.r32 |= port->APEMode2Enable.r32;
+    Network_setEnableState(port);
 
     // Ensure REG_RECEIVE_MAC_MODE has ENABLE set.
     // I recommend also setting APE_PROMISCUOUS_MODE and PROMISCUOUS_MODE,
@@ -993,8 +996,6 @@ void Network_InitPort(NetworkPort_t *port, reload_type_t reset_phy)
 
     port->device->GrcModeControl.bits.HostStackUp = 1; // Enable packet RX
 
-    APE_aquireLock();
-
     Network_updatePortState(port);
 
     uint16_t status_value = MII_readRegister(port->device, phy, (mii_reg_t)REG_MII_STATUS);
@@ -1032,6 +1033,8 @@ void Network_checkPortState(NetworkPort_t *port)
             port->link_state_printed = true;
         }
 
+        APE_aquireLock();
+
         // Update state to match latest.
         if (Network_updatePortState(port))
         {
@@ -1046,6 +1049,8 @@ void Network_checkPortState(NetworkPort_t *port)
             printf("Link Status Updated\n");
             port->link_state_printed = false;
         }
+
+        APE_releaseLock();
     }
 }
 
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