at86rf2xx: cancel receiving when preparing for TX

drivers/at86rf2xx/at86rf2xx.c

@@ -215,9 +215,13 @@ void at86rf2xx_tx_prepare(at86rf2xx_t *dev)
     do {
         state = at86rf2xx_get_status(dev);
     }
-    while (state == AT86RF2XX_STATE_BUSY_RX_AACK ||
-           state == AT86RF2XX_STATE_BUSY_TX_ARET);
-    if (state != AT86RF2XX_STATE_TX_ARET_ON) {
+    while (state == AT86RF2XX_STATE_BUSY_TX_ARET);
+
+    /* if receiving cancel */
+    if(state == AT86RF2XX_STATE_BUSY_RX_AACK) {
+        at86rf2xx_force_trx_off(dev);
+        dev->idle_state = AT86RF2XX_STATE_RX_AACK_ON;
+    } else if (state != AT86RF2XX_STATE_TX_ARET_ON) {
         dev->idle_state = state;
     }
     at86rf2xx_set_state(dev, AT86RF2XX_STATE_TX_ARET_ON);

drivers/at86rf2xx/at86rf2xx_getset.c

@@ -401,12 +401,6 @@ static inline void _set_state(at86rf2xx_t *dev, uint8_t state)
     while (at86rf2xx_get_status(dev) != state);
 }
 
-static inline void _force_trx_off(at86rf2xx_t *dev)
-{
-    at86rf2xx_reg_write(dev, AT86RF2XX_REG__TRX_STATE, AT86RF2XX_TRX_STATE__FORCE_TRX_OFF);
-    while (at86rf2xx_get_status(dev) != AT86RF2XX_STATE_TRX_OFF);
-}
-
 void at86rf2xx_set_state(at86rf2xx_t *dev, uint8_t state)
 {
     uint8_t old_state = at86rf2xx_get_status(dev);
@@ -438,7 +432,7 @@ void at86rf2xx_set_state(at86rf2xx_t *dev, uint8_t state)
 
     if (state == AT86RF2XX_STATE_SLEEP) {
         /* First go to TRX_OFF */
-        _force_trx_off(dev);
+        at86rf2xx_force_trx_off(dev);
         /* Go to SLEEP mode from TRX_OFF */
         gpio_set(dev->sleep_pin);
     } else {
@@ -458,5 +452,5 @@ void at86rf2xx_reset_state_machine(at86rf2xx_t *dev)
         old_state = at86rf2xx_get_status(dev);
     } while (old_state == AT86RF2XX_STATE_IN_PROGRESS);
 
-    _force_trx_off(dev);
+    at86rf2xx_force_trx_off(dev);
 }

drivers/at86rf2xx/at86rf2xx_internal.c

@@ -104,3 +104,11 @@ uint8_t at86rf2xx_get_status(const at86rf2xx_t *dev)
     return (at86rf2xx_reg_read(dev, AT86RF2XX_REG__TRX_STATUS)
             & AT86RF2XX_TRX_STATUS_MASK__TRX_STATUS);
 }
+
+void at86rf2xx_force_trx_off(const at86rf2xx_t *dev)
+{
+    at86rf2xx_reg_write(dev,
+                        AT86RF2XX_REG__TRX_STATE,
+                        AT86RF2XX_TRX_STATE__FORCE_TRX_OFF);
+    while (at86rf2xx_get_status(dev) != AT86RF2XX_STATE_TRX_OFF);
+}

drivers/at86rf2xx/include/at86rf2xx_internal.h

@@ -90,6 +90,13 @@ void at86rf2xx_sram_write(const at86rf2xx_t *dev,
 void at86rf2xx_fb_read(const at86rf2xx_t *dev,
                        uint8_t *data, const size_t len);
 
+/**
+ * @brief   Cancel ongoing transactions and switch to TRX_OFF state
+ *
+ * @param[in] dev       device to manipulate
+ */
+void at86rf2xx_force_trx_off(const at86rf2xx_t *dev);
+
 /**
  * @brief   Convenience function for reading the status of the given device
  *