From e384f1e5020f48b20819c024afc2968ffa0739b2 Mon Sep 17 00:00:00 2001
From: Gunar Schorcht <gunar@schorcht.net>
Date: Wed, 23 Jan 2019 10:32:44 +0100
Subject: [PATCH] cpu/esp8266: send timeout handling in esp_wifi
A timeout was introduced if sending a frame takes to long time. In that case the WiFi interface disconnects and reconnects automatically to recover.
---
cpu/esp8266/esp-wifi/esp_wifi_netdev.c | 26 +++++++++++++++++++++-----
1 file changed, 21 insertions(+), 5 deletions(-)
diff --git a/cpu/esp8266/esp-wifi/esp_wifi_netdev.c b/cpu/esp8266/esp-wifi/esp_wifi_netdev.c
index 2e8f846207..cd1d58561f 100644
--- a/cpu/esp8266/esp-wifi/esp_wifi_netdev.c
+++ b/cpu/esp8266/esp-wifi/esp_wifi_netdev.c
@@ -64,6 +64,8 @@
#define ESP_WIFI_SOFTAP_IF (SOFTAP_IF)
#define ESP_WIFI_RECONNECT_TIME (20 * US_PER_SEC)
+#define ESP_WIFI_SEND_TIMEOUT (MS_PER_SEC)
+
#define MAC_STR "%02x:%02x:%02x:%02x:%02x:%02x"
#define MAC_STR_ARG(m) m[0], m[1], m[2], m[3], m[4], m[5]
/** Timer used to reconnect automatically after 20 seconds if not connected */
@@ -380,9 +382,22 @@ static int IRAM _send(netdev_t *netdev, const iolist_t *iolist)
#endif /* ENABLE_DEBUG */
int res = ieee80211_output_pbuf(sta_netif, pb);
+
+ /*
+ * Attempting to send the next frame before completing the transmission
+ * of the previous frame may result in a complete blockage of the send
+ * function. To avoid this blockage, we have to wait here until the frame
+ * has been sent. The frame has been sent when pb->ref becomes 1.
+ * We wait for a maximum time of ESP_WIFI_SEND_TIMEOUT milliseconds.
+ */
+ unsigned _timeout = ESP_WIFI_SEND_TIMEOUT;
+ while (pb->ref > 1 && --_timeout && dev->state == ESP_WIFI_CONNECTED) {
+ xtimer_usleep(US_PER_MS);
+ }
pbuf_free(pb);
- if (res == ERR_OK) {
+ if (res == ERR_OK && _timeout) {
+ /* There was no ieee80211_output_pbuf error and no send timeout. */
#ifdef MODULE_NETSTATS_L2
netdev->stats.tx_bytes += iol_len;
netdev->event_callback(netdev, NETDEV_EVENT_TX_COMPLETE);
@@ -392,16 +407,17 @@ static int IRAM _send(netdev_t *netdev, const iolist_t *iolist)
return iol_len;
}
else {
+ /* There was either a ieee80211_output_pbuf error or send timed out. */
#ifdef MODULE_NETSTATS_L2
netdev->stats.tx_failed++;
#endif
_in_send = false;
critical_exit();
/*
- * This error usually happens because we run into out of memory. We have
- * to wait until lwIP pbuf has been flushed. For that purpose, we
- * have to disconnect from AP and wait for a short time. The node will
- * then reconnect to AP automatically.
+ * ieee80211_output_pbuf usually happens because we run into out of
+ * memory. We have to wait until lwIP pbuf has been flushed. For that
+ * purpose, we have to disconnect from AP and wait for a short time.
+ * The node will then reconnect to AP automatically.
*/
wifi_station_disconnect();
return -EIO;
--
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