From 37cd0404e54cf26f6b3fe0d3cd193f7a54778118 Mon Sep 17 00:00:00 2001
From: jflyper <shinoda@jaist.ac.jp>
Date: Tue, 24 Apr 2018 07:42:46 +0900
Subject: [PATCH 1/3] Prevent channel.ccr to be deferenced if timer failed to
 initialize

---
 src/main/drivers/pwm_output.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/main/drivers/pwm_output.c b/src/main/drivers/pwm_output.c
index 9d6f57bc00..ff01904712 100644
--- a/src/main/drivers/pwm_output.c
+++ b/src/main/drivers/pwm_output.c
@@ -487,9 +487,11 @@ void pwmToggleBeeper(void)
 
 void beeperPwmInit(const ioTag_t tag, uint16_t frequency)
 {
-        beeperPwm.io = IOGetByTag(tag);
         const timerHardware_t *timer = timerGetByTag(tag, TIM_USE_BEEPER);
-        if (beeperPwm.io && timer) {
+        IO_t beeperIO = IOGetByTag(tag);
+
+        if (beeperIO && timer) {
+            beeperPwm.io = beeperIO;
             IOInit(beeperPwm.io, OWNER_BEEPER, RESOURCE_INDEX(0));
 #if defined(USE_HAL_DRIVER)
             IOConfigGPIOAF(beeperPwm.io, IOCFG_AF_PP, timer->alternateFunction);
@@ -498,8 +500,9 @@ void beeperPwmInit(const ioTag_t tag, uint16_t frequency)
 #endif
             freqBeep = frequency;
             pwmOutConfig(&beeperPwm.channel, timer, PWM_TIMER_1MHZ, PWM_TIMER_1MHZ / freqBeep, (PWM_TIMER_1MHZ / freqBeep) / 2, 0);
+
+            *beeperPwm.channel.ccr = 0;
+            beeperPwm.enabled = false;
         }
-        *beeperPwm.channel.ccr = 0;
-        beeperPwm.enabled = false;
 }
 #endif

From 22a7788fa373e32159a87725b3577ba4e90f7d30 Mon Sep 17 00:00:00 2001
From: jflyper <shinoda@jaist.ac.jp>
Date: Tue, 24 Apr 2018 08:02:32 +0900
Subject: [PATCH 2/3] Reset beeper_frequency if valid timer is not found

---
 src/main/fc/config.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/main/fc/config.c b/src/main/fc/config.c
index 40e8ab6c95..ba5f655416 100644
--- a/src/main/fc/config.c
+++ b/src/main/fc/config.c
@@ -50,6 +50,7 @@
 #include "io/serial.h"
 
 #include "pg/beeper.h"
+#include "pg/beeper_dev.h"
 #include "pg/pg.h"
 #include "pg/pg_ids.h"
 
@@ -356,6 +357,12 @@ static void validateAndFixConfig(void)
     featureClear(FEATURE_RSSI_ADC);
 #endif
 
+#if defined(USE_BEEPER)
+    if (beeperDevConfig()->frequency && !timerGetByTag(beeperDevConfig()->ioTag, TIM_USE_BEEPER)) {
+        beeperDevConfigMutable()->frequency = 0;
+    }
+#endif
+
 #if defined(TARGET_VALIDATECONFIG)
     targetValidateConfiguration();
 #endif

From e87d14fe46563fd96b701038b3aec268a785af12 Mon Sep 17 00:00:00 2001
From: jflyper <shinoda@jaist.ac.jp>
Date: Tue, 24 Apr 2018 07:43:59 +0900
Subject: [PATCH 3/3] White space tidy & add braces

---
 src/main/drivers/pwm_output.c | 46 ++++++++++++++++++-----------------
 1 file changed, 24 insertions(+), 22 deletions(-)

diff --git a/src/main/drivers/pwm_output.c b/src/main/drivers/pwm_output.c
index ff01904712..e6d735568d 100644
--- a/src/main/drivers/pwm_output.c
+++ b/src/main/drivers/pwm_output.c
@@ -469,40 +469,42 @@ void servoDevInit(const servoDevConfig_t *servoConfig)
 #ifdef USE_BEEPER
 void pwmWriteBeeper(bool onoffBeep)
 {
-        if (!beeperPwm.io)
-            return;
-        if (onoffBeep == true) {
-            *beeperPwm.channel.ccr = (PWM_TIMER_1MHZ / freqBeep) / 2;
-            beeperPwm.enabled = true;
-        } else {
-            *beeperPwm.channel.ccr = 0;
-            beeperPwm.enabled = false;
-        }
+    if (!beeperPwm.io) {
+        return;
+    }
+
+    if (onoffBeep == true) {
+        *beeperPwm.channel.ccr = (PWM_TIMER_1MHZ / freqBeep) / 2;
+        beeperPwm.enabled = true;
+    } else {
+        *beeperPwm.channel.ccr = 0;
+        beeperPwm.enabled = false;
+    }
 }
 
 void pwmToggleBeeper(void)
 {
-        pwmWriteBeeper(!beeperPwm.enabled);
+    pwmWriteBeeper(!beeperPwm.enabled);
 }
 
 void beeperPwmInit(const ioTag_t tag, uint16_t frequency)
 {
-        const timerHardware_t *timer = timerGetByTag(tag, TIM_USE_BEEPER);
-        IO_t beeperIO = IOGetByTag(tag);
+    const timerHardware_t *timer = timerGetByTag(tag, TIM_USE_BEEPER);
+    IO_t beeperIO = IOGetByTag(tag);
 
-        if (beeperIO && timer) {
-            beeperPwm.io = beeperIO;
-            IOInit(beeperPwm.io, OWNER_BEEPER, RESOURCE_INDEX(0));
+    if (beeperIO && timer) {
+        beeperPwm.io = beeperIO;
+        IOInit(beeperPwm.io, OWNER_BEEPER, RESOURCE_INDEX(0));
 #if defined(USE_HAL_DRIVER)
-            IOConfigGPIOAF(beeperPwm.io, IOCFG_AF_PP, timer->alternateFunction);
+        IOConfigGPIOAF(beeperPwm.io, IOCFG_AF_PP, timer->alternateFunction);
 #else
-            IOConfigGPIO(beeperPwm.io, IOCFG_AF_PP);
+        IOConfigGPIO(beeperPwm.io, IOCFG_AF_PP);
 #endif
-            freqBeep = frequency;
-            pwmOutConfig(&beeperPwm.channel, timer, PWM_TIMER_1MHZ, PWM_TIMER_1MHZ / freqBeep, (PWM_TIMER_1MHZ / freqBeep) / 2, 0);
+        freqBeep = frequency;
+        pwmOutConfig(&beeperPwm.channel, timer, PWM_TIMER_1MHZ, PWM_TIMER_1MHZ / freqBeep, (PWM_TIMER_1MHZ / freqBeep) / 2, 0);
 
-            *beeperPwm.channel.ccr = 0;
-            beeperPwm.enabled = false;
-        }
+        *beeperPwm.channel.ccr = 0;
+        beeperPwm.enabled = false;
+    }
 }
 #endif