From 0115ff15b2b1323c36e613a6234b7fd9921c3d7d Mon Sep 17 00:00:00 2001
From: Andrey Mironov <diehertz@gmail.com>
Date: Mon, 23 Jul 2018 23:31:42 +0300
Subject: [PATCH] Fixed init order of MAX7456 DisplayPort

---
 src/main/drivers/max7456.c        |  7 ++++---
 src/main/drivers/max7456.h        |  2 +-
 src/main/io/displayport_max7456.c | 11 ++++++++---
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/src/main/drivers/max7456.c b/src/main/drivers/max7456.c
index 98add73dfc..e237b44b7b 100644
--- a/src/main/drivers/max7456.c
+++ b/src/main/drivers/max7456.c
@@ -415,18 +415,18 @@ void max7456ReInit(void)
 // Here we init only CS and try to init MAX for first time.
 // Also detect device type (MAX v.s. AT)
 
-void max7456Init(const max7456Config_t *max7456Config, const vcdProfile_t *pVcdProfile, bool cpuOverclock)
+bool max7456Init(const max7456Config_t *max7456Config, const vcdProfile_t *pVcdProfile, bool cpuOverclock)
 {
     max7456HardwareReset();
 
     if (!max7456Config->csTag) {
-        return;
+        return false;
     }
 
     busdev->busdev_u.spi.csnPin = IOGetByTag(max7456Config->csTag);
 
     if (!IOIsFreeOrPreinit(busdev->busdev_u.spi.csnPin)) {
-        return;
+        return false;
     }
 
     IOInit(busdev->busdev_u.spi.csnPin, OWNER_OSD_CS, 0);
@@ -489,6 +489,7 @@ void max7456Init(const max7456Config_t *max7456Config, const vcdProfile_t *pVcdP
 #endif
 
     // Real init will be made later when driver detect idle.
+    return true;
 }
 
 /**
diff --git a/src/main/drivers/max7456.h b/src/main/drivers/max7456.h
index 95b55695cf..c5327ddfaa 100644
--- a/src/main/drivers/max7456.h
+++ b/src/main/drivers/max7456.h
@@ -31,7 +31,7 @@ extern uint16_t maxScreenSize;
 struct vcdProfile_s;
 void    max7456HardwareReset(void);
 struct max7456Config_s;
-void    max7456Init(const struct max7456Config_s *max7456Config, const struct vcdProfile_s *vcdProfile, bool cpuOverclock);
+bool    max7456Init(const struct max7456Config_s *max7456Config, const struct vcdProfile_s *vcdProfile, bool cpuOverclock);
 void    max7456Invert(bool invert);
 void    max7456Brightness(uint8_t black, uint8_t white);
 void    max7456DrawScreen(void);
diff --git a/src/main/io/displayport_max7456.c b/src/main/io/displayport_max7456.c
index f865c2b997..accf9abd74 100644
--- a/src/main/io/displayport_max7456.c
+++ b/src/main/io/displayport_max7456.c
@@ -166,12 +166,17 @@ static const displayPortVTable_t max7456VTable = {
 
 displayPort_t *max7456DisplayPortInit(const vcdProfile_t *vcdProfile)
 {
-    displayInit(&max7456DisplayPort, &max7456VTable);
 #ifdef USE_OSD_SLAVE
-    max7456Init(max7456Config(), vcdProfile, false);
+    if (!max7456Init(max7456Config(), vcdProfile, false))
 #else
-    max7456Init(max7456Config(), vcdProfile, systemConfig()->cpu_overclock);
+    if (!max7456Init(max7456Config(), vcdProfile, systemConfig()->cpu_overclock))
 #endif
+    {
+        return NULL;
+    }
+
+    displayInit(&max7456DisplayPort, &max7456VTable);
+
     resync(&max7456DisplayPort);
     return &max7456DisplayPort;
 }