drivers/kw2xrf: finish ongoing transmission before sending next frame

drivers/Makefile.dep

@@ -142,6 +142,7 @@ ifneq (,$(filter kw2xrf,$(USEMODULE)))
   USEMODULE += netif
   USEMODULE += ieee802154
   USEMODULE += netdev_ieee802154
+  USEMODULE += core_thread_flags
   FEATURES_REQUIRED += periph_spi
 endif
 

drivers/include/kw2xrf.h

@@ -31,6 +31,7 @@
 #include "net/netdev.h"
 #include "net/netdev/ieee802154.h"
 #include "net/gnrc/nettype.h"
+#include "thread.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -129,6 +130,7 @@ typedef struct {
      * @brief   device specific fields
      * @{
      */
+    thread_t *thread;                   /**< Network driver thread, for providing feedback from IRQ handler */
     kw2xrf_params_t params;             /**< parameters for initialization */
     uint8_t buf[KW2XRF_MAX_PKT_LENGTH]; /**< Buffer for incoming or outgoing packets */
     uint8_t state;                      /**< current state of the radio */

drivers/kw2xrf/kw2xrf_netdev.c

@@ -1,5 +1,7 @@
 /*
  * Copyright (C) 2016 Phytec Messtechnik GmbH
+                 2017 HAW Hamburg
+                 2017 SKF AB
  *
  * This file is subject to the terms and conditions of the GNU Lesser
  * General Public License v2.1. See the file LICENSE in the top level
@@ -13,7 +15,9 @@
  * @file
  * @brief       Netdev interface for kw2xrf drivers
  *
- * @author      Johann Fischer <j.fischer@phytec.de>
+ * @author      Johann Fischer  <j.fischer@phytec.de>
+ * @author      Peter Kietzmann <peter.kietzmann@haw-hamburg.de>
+ * @author      Joakim Nohlgård <joakim.nohlgard@eistec.se>
  */
 
 #include <string.h>
@@ -21,6 +25,7 @@
 #include <errno.h>
 
 #include "log.h"
+#include "thread_flags.h"
 #include "net/eui64.h"
 #include "net/ieee802154.h"
 #include "net/netdev.h"
@@ -41,14 +46,28 @@
 
 #define _MACACKWAITDURATION         (864 / 16) /* 864us * 62500Hz */
 
+#define KW2XRF_THREAD_FLAG_ISR      (1 << 8)
+
+static volatile unsigned int num_irqs_queued = 0;
+static volatile unsigned int num_irqs_handled = 0;
+static unsigned int spinning_for_irq = 0;
 static uint8_t _send_last_fcf;
 
+static void _isr(netdev_t *netdev);
+
 static void _irq_handler(void *arg)
 {
-    netdev_t *dev = (netdev_t *) arg;
+    netdev_t *netdev = (netdev_t *) arg;
+    kw2xrf_t *dev = (kw2xrf_t *)netdev;
 
-    if (dev->event_callback) {
+    thread_flags_set(dev->thread, KW2XRF_THREAD_FLAG_ISR);
-        dev->event_callback(dev, NETDEV_EVENT_ISR);
+
+    /* We use this counter to avoid filling the message queue with redundant ISR events */
+    if (num_irqs_queued == num_irqs_handled) {
+        ++num_irqs_queued;
+        if (netdev->event_callback) {
+            netdev->event_callback(netdev, NETDEV_EVENT_ISR);
+        }
     }
 }
 
@@ -56,6 +75,8 @@ static int _init(netdev_t *netdev)
 {
     kw2xrf_t *dev = (kw2xrf_t *)netdev;
 
+    dev->thread = (thread_t *)thread_get(thread_getpid());
+
     /* initialize SPI and GPIOs */
     if (kw2xrf_init(dev, &_irq_handler)) {
         LOG_ERROR("[kw2xrf] unable to initialize device\n");
@@ -91,6 +112,32 @@ static void kw2xrf_tx_exec(kw2xrf_t *dev)
     }
 }
 
+static void kw2xrf_wait_idle(kw2xrf_t *dev)
+{
+    /* make sure any ongoing T or TR sequence is finished */
+    if (kw2xrf_can_switch_to_idle(dev) == 0) {
+        DEBUG("[kw2xrf] TX already in progress\n");
+        num_irqs_handled = num_irqs_queued;
+        spinning_for_irq = 1;
+        thread_flags_clear(KW2XRF_THREAD_FLAG_ISR);
+        while (1) {
+            /* TX in progress */
+            /* Handle any outstanding IRQ first */
+            _isr((netdev_t *)dev);
+            /* _isr() will switch the transceiver back to idle after
+             * handling the TX complete IRQ */
+            if (kw2xrf_can_switch_to_idle(dev)) {
+                break;
+            }
+            /* Block until we get another IRQ */
+            thread_flags_wait_any(KW2XRF_THREAD_FLAG_ISR);
+            DEBUG("[kw2xrf] waited ISR\n");
+        }
+        spinning_for_irq = 0;
+        DEBUG("[kw2xrf] previous TX done\n");
+    }
+}
+
 static int _send(netdev_t *netdev, const struct iovec *vector, unsigned count)
 {
     kw2xrf_t *dev = (kw2xrf_t *)netdev;
@@ -98,6 +145,9 @@ static int _send(netdev_t *netdev, const struct iovec *vector, unsigned count)
     uint8_t *pkt_buf = &(dev->buf[1]);
     size_t len = 0;
 
+    /* wait for ongoing transmissions to finish */
+    kw2xrf_wait_idle(dev);
+
     /* load packet data into buffer */
     for (unsigned i = 0; i < count; i++, ptr++) {
         /* current packet data + FCS too long */
@@ -109,15 +159,8 @@ static int _send(netdev_t *netdev, const struct iovec *vector, unsigned count)
         len = kw2xrf_tx_load(pkt_buf, ptr->iov_base, ptr->iov_len, len);
     }
 
-    /* make sure ongoing t or tr sequenz are finished */
+    kw2xrf_set_sequence(dev, XCVSEQ_IDLE);
-    if (kw2xrf_can_switch_to_idle(dev)) {
+    dev->pending_tx++;
-        kw2xrf_set_sequence(dev, XCVSEQ_IDLE);
-        dev->pending_tx++;
-    }
-    else {
-        /* do not wait, this can lead to a dead lock */
-        return 0;
-    }
 
     /*
      * Nbytes = FRAME_LEN - 2 -> FRAME_LEN = Nbytes + 2
@@ -690,6 +733,9 @@ static void _isr(netdev_t *netdev)
 {
     uint8_t dregs[MKW2XDM_PHY_CTRL4 + 1];
     kw2xrf_t *dev = (kw2xrf_t *)netdev;
+    if (!spinning_for_irq) {
+        num_irqs_handled = num_irqs_queued;
+    }
 
     kw2xrf_read_dregs(dev, MKW2XDM_IRQSTS1, dregs, MKW2XDM_PHY_CTRL4 + 1);
     kw2xrf_mask_irq_b(dev);