From 093eb7a985b42da6ec2a881e092b59cc97c8c4aa Mon Sep 17 00:00:00 2001
From: Thomas Eichinger <thomas.eichinger1@gmail.com>
Date: Fri, 7 Jul 2017 09:11:28 -0700
Subject: [PATCH] drivers/at86rf2xx: remove `at86rf2xx_reset_state_machine`

This function was only used once in the initialization procedure.
Inlining the actual state change reduces overhead and lines to
maintain.

If ever needed, undo this commit.
---
 drivers/at86rf2xx/at86rf2xx.c          |  4 +++-
 drivers/at86rf2xx/at86rf2xx_getset.c   | 20 +++-----------------
 drivers/at86rf2xx/at86rf2xx_internal.c | 10 +++++-----
 drivers/include/at86rf2xx.h            | 11 -----------
 4 files changed, 11 insertions(+), 34 deletions(-)

diff --git a/drivers/at86rf2xx/at86rf2xx.c b/drivers/at86rf2xx/at86rf2xx.c
index acae63783a..73e22f0a59 100644
--- a/drivers/at86rf2xx/at86rf2xx.c
+++ b/drivers/at86rf2xx/at86rf2xx.c
@@ -56,7 +56,9 @@ void at86rf2xx_reset(at86rf2xx_t *dev)
     at86rf2xx_hardware_reset(dev);
 
     /* Reset state machine to ensure a known state */
-    at86rf2xx_reset_state_machine(dev);
+    if (dev->state == AT86RF2XX_STATE_P_ON) {
+        at86rf2xx_set_state(dev, AT86RF2XX_STATE_FORCE_TRX_OFF);
+    }
 
     /* reset options and sequence number */
     dev->netdev.seq = 0;
diff --git a/drivers/at86rf2xx/at86rf2xx_getset.c b/drivers/at86rf2xx/at86rf2xx_getset.c
index 5b9a615cd0..4a50675c45 100644
--- a/drivers/at86rf2xx/at86rf2xx_getset.c
+++ b/drivers/at86rf2xx/at86rf2xx_getset.c
@@ -440,9 +440,9 @@ static inline void _set_state(at86rf2xx_t *dev, uint8_t state, uint8_t cmd)
     if (state != AT86RF2XX_STATE_RX_AACK_ON) {
         while (at86rf2xx_get_status(dev) != state) {}
     }
-    /* Although RX_AACK_ON state doesn't get read back, 
-     * at least make sure if state transition is in progress or not 
-     */ 
+    /* Although RX_AACK_ON state doesn't get read back,
+     * at least make sure if state transition is in progress or not
+     */
     else {
         while (at86rf2xx_get_status(dev) == AT86RF2XX_STATE_IN_PROGRESS) {}
     }
@@ -498,17 +498,3 @@ uint8_t at86rf2xx_set_state(at86rf2xx_t *dev, uint8_t state)
 
     return old_state;
 }
-
-void at86rf2xx_reset_state_machine(at86rf2xx_t *dev)
-{
-    uint8_t old_state;
-
-    at86rf2xx_assert_awake(dev);
-
-    /* Wait for any state transitions to complete before forcing TRX_OFF */
-    do {
-        old_state = at86rf2xx_get_status(dev);
-    } while (old_state == AT86RF2XX_STATE_IN_PROGRESS);
-
-    at86rf2xx_set_state(dev, AT86RF2XX_STATE_FORCE_TRX_OFF);
-}
diff --git a/drivers/at86rf2xx/at86rf2xx_internal.c b/drivers/at86rf2xx/at86rf2xx_internal.c
index 9db91e78d7..26d1c8e0f7 100644
--- a/drivers/at86rf2xx/at86rf2xx_internal.c
+++ b/drivers/at86rf2xx/at86rf2xx_internal.c
@@ -127,9 +127,9 @@ void at86rf2xx_assert_awake(at86rf2xx_t *dev)
         gpio_clear(dev->params.sleep_pin);
         xtimer_usleep(AT86RF2XX_WAKEUP_DELAY);
 
-        /* update state: on some platforms, the timer behind xtimer 
-         * may be inaccurate or the radio itself may take longer 
-         * to wake up due to extra capacitance on the oscillator. 
+        /* update state: on some platforms, the timer behind xtimer
+         * may be inaccurate or the radio itself may take longer
+         * to wake up due to extra capacitance on the oscillator.
          * Spin until we are actually awake
          */
         do {
@@ -147,8 +147,8 @@ void at86rf2xx_hardware_reset(at86rf2xx_t *dev)
     gpio_set(dev->params.reset_pin);
     xtimer_usleep(AT86RF2XX_RESET_DELAY);
 
-    /* update state: if the radio state was P_ON (initialization phase), 
-     * it remains P_ON. Otherwise, it should go to TRX_OFF 
+    /* update state: if the radio state was P_ON (initialization phase),
+     * it remains P_ON. Otherwise, it should go to TRX_OFF
      */
     do {
         dev->state = at86rf2xx_reg_read(dev, AT86RF2XX_REG__TRX_STATUS) &
diff --git a/drivers/include/at86rf2xx.h b/drivers/include/at86rf2xx.h
index aa5df2a86e..66527f61da 100644
--- a/drivers/include/at86rf2xx.h
+++ b/drivers/include/at86rf2xx.h
@@ -391,17 +391,6 @@ void at86rf2xx_set_option(at86rf2xx_t *dev, uint16_t option, bool state);
  */
 uint8_t at86rf2xx_set_state(at86rf2xx_t *dev, uint8_t state);
 
-/**
- * @brief   Reset the internal state machine to TRX_OFF mode.
- *
- * This will force a transition to TRX_OFF regardless of whether the transceiver
- * is currently busy sending or receiving. This function is used to get back to
- * a known state during driver initialization.
- *
- * @param[in] dev           device to operate on
- */
-void at86rf2xx_reset_state_machine(at86rf2xx_t *dev);
-
 /**
  * @brief   Convenience function for simply sending data
  *