fix race condition

.gitignore

@@ -0,0 +1 @@
+copy.sh

lora_sx127.c

@@ -37,9 +37,10 @@
  *
  */
 
-#define DEBUG
 #define SX127X_LEGACY_KERNEL
 
+#define DEBUG
+
 #include <linux/module.h>
 #include <linux/timer.h>
 #include <linux/device.h>
@@ -50,28 +51,9 @@
 #include <linux/regmap.h>
 #include <net/mac802154.h>
 
-#ifndef F_XOSC
+static unsigned tx_poll_div = 10;
-#define F_XOSC		32000000
+module_param(tx_poll_div, uint, 0000);
-#endif
+MODULE_PARM_DESC(tx_poll_div, "Number of RX poll cycles to perform before attempting a single TX op");
-static u32 xosc_frq = F_XOSC;
-module_param(xosc_frq, uint, 0000);
-MODULE_PARM_DESC(xosc_frq, "Crystal oscillator frequency of the LoRa chip");
-
-#define	__POW_2_19	0x80000
-
-#ifndef SX127X_SPRF
-#define SX127X_SPRF	512
-#endif
-static u32 sprf = SX127X_SPRF;
-module_param(sprf, uint, 0000);
-MODULE_PARM_DESC(sprf, "Spreading factor of Chirp Spread Spectrum modulation");
-
-#ifndef SX127X_RX_BYTE_TIMEOUT
-#define SX127X_RX_BYTE_TIMEOUT	1023
-#endif
-static u32 rx_timeout = SX127X_RX_BYTE_TIMEOUT;
-module_param(rx_timeout, uint, 0000);
-MODULE_PARM_DESC(rx_timeout, "RX time-out value as number of symbols");
 
 /* SX127X Registers addresses */
 #define SX127X_REG_FIFO				0x00
@@ -167,10 +149,6 @@ MODULE_PARM_DESC(rx_timeout, "RX time-out value as number of symbols");
 #define SX127X_MODEM_CONFIG1_HEADER_MODE_EXPLICIT	0x00
 #define SX127X_MODEM_CONFIG1_HEADER_MODE_IMPLICIT	0x01
 
-#define SX127X_MODEM_CONFIG2_RXPAYLOADCRCON		0x04
-
-#define SX127X_MODEM_CONFIG3_AGCAUTOON			0x04
-
 /* SX127X's RX/TX FIFO base address */
 #define SX127X_FIFO_RX_BASE_ADDRESS		0x00
 #define SX127X_FIFO_TX_BASE_ADDRESS		0x80
@@ -186,6 +164,7 @@ struct sx127x {
 	bool                  busy;
 	struct sk_buff       *tx_skb;
 	size_t                delayed_tx_length;
+	unsigned              tx_wait;
 
 	struct timer_list     poll_timer;
 	struct work_struct    poll_work;
@@ -316,7 +295,7 @@ static int sx127x_set_tx_power(struct sx127x *hw, int level)
 
 static int sx127x_init(struct sx127x *hw, u8 *major, u8 *minor)
 {
-	u8 modem_config1, modem_config2, lna, version;
+	u8 modem_config1, lna, version;
 	int ret;
 
 	ret = sx127x_reg_read(hw, SX127X_REG_VERSION, &version);
@@ -358,23 +337,14 @@ static int sx127x_init(struct sx127x *hw, u8 *major, u8 *minor)
 	if (ret < 0)
 		return ret;
 
-	ret = sx127x_reg_read(hw, SX127X_REG_MODEM_CONFIG2, &modem_config2);
-	if (ret < 0)
-		return ret;
-
 	modem_config1 &= ~SX127X_MODEM_CONFIG1_HEADER_MODE_MASK;
 	modem_config1 |= SX127X_MODEM_CONFIG1_HEADER_MODE_EXPLICIT;
-	modem_config2 |= SX127X_MODEM_CONFIG2_RXPAYLOADCRCON;
 
 	ret = sx127x_reg_write(hw, SX127X_REG_MODEM_CONFIG1, modem_config1);
 	if (ret < 0)
 		return ret;
 
-	ret = sx127x_reg_write(hw, SX127X_REG_MODEM_CONFIG2, modem_config2);
+	ret = sx127x_reg_write(hw, SX127X_REG_MODEM_CONFIG3, 0x4);
-	if (ret < 0)
-		return ret;
-
-	ret = sx127x_reg_write(hw, SX127X_REG_MODEM_CONFIG3, SX127X_MODEM_CONFIG3_AGCAUTOON);
 	if (ret < 0)
 		return ret;
 
@@ -526,9 +496,6 @@ static void sx127x_poll_work(struct work_struct *work)
 		if (!rx_skb)
 			goto exit_busy;
 
-		if (rx_length > IEEE802154_MTU)
-			rx_length = IEEE802154_MTU;
-
 		rx_data = skb_put(rx_skb, rx_length);
 		while (rx_length--)
 			if (sx127x_reg_read(hw, SX127X_REG_FIFO, rx_data++) < 0)
@@ -545,7 +512,10 @@ static void sx127x_poll_work(struct work_struct *work)
 		goto exit_busy;
 
 	if ((mode & SX127X_MODE_MASK) != SX127X_TX_MODE) {
-		if (hw->delayed_tx_length) {
+		if (++hw->tx_wait >= tx_poll_div)
+			hw->tx_wait = 0;
+
+		if (hw->delayed_tx_length && hw->tx_wait == 0) {
 			sx127x_mode(hw, SX127X_TX_MODE);
 			hw->delayed_tx_length = 0;
 		} else if ((mode & SX127X_MODE_MASK) != SX127X_RXCONTINUOUS_MODE)
@@ -562,14 +532,14 @@ exit_busy:
 	if (rx_skb)
 		kfree_skb(rx_skb);
 
-	if (tx_skb)
-		ieee802154_xmit_complete(hw->ieee, tx_skb, false);
-
 	spin_lock_irqsave(&hw->lock, spin_irq);
 	hw->busy = false;
 	if (tx_skb)
 		hw->tx_skb = NULL;
 	spin_unlock_irqrestore(&hw->lock, spin_irq);
+
+	if (tx_skb)
+		ieee802154_xmit_complete(hw->ieee, tx_skb, false);
 }
 
 static void sx127x_poll_timer(struct timer_list *timer)
@@ -592,7 +562,9 @@ static int sx127x_802154_xmit_async(struct ieee802154_hw *ieee, struct sk_buff *
 		ret = -EBUSY;
 	spin_unlock_irqrestore(&hw->lock, spin_irq);
 
-	schedule_work(&hw->tx_work);
+	if (!ret)
+		schedule_work(&hw->tx_work);
+
 	return ret;
 }
 
@@ -629,7 +601,6 @@ static int sx127x_802154_start(struct ieee802154_hw *ieee)
 	}
 
 	mod_timer(&hw->poll_timer, jiffies + POLL_JIFFIES);
-	dev_dbg(regmap_get_device(hw->regmap), "%s\n", __func__);
 	return 0;
 }
 
@@ -641,7 +612,6 @@ static void sx127x_802154_stop(struct ieee802154_hw *ieee)
 	cancel_work_sync(&hw->poll_work);
 
 	(void) sx127x_mode(hw, SX127X_SLEEP_MODE);
-	dev_dbg(regmap_get_device(hw->regmap), "%s\n", __func__);
 }
 
 static int sx127x_802154_set_promiscuous_mode(struct ieee802154_hw *ieee, const bool on)
@@ -700,6 +670,7 @@ static int sx127x_spi_probe(struct spi_device *spi)
 	hw->spi = spi;
 	hw->ieee = ieee;
 	hw->busy = false;
+	hw->tx_wait = 0;
 	hw->delayed_tx_length = 0;
 	spin_lock_init(&hw->lock);
 
@@ -774,6 +745,30 @@ static int sx127x_spi_probe(struct spi_device *spi)
 		dev_err(&spi->dev, "ieee802154_register_hw() failed: %d\n", ret);
 
 	return ret;
+	/*u8 buffer[] = { 0x36, 0x39 }; // 69?
+	ret = sx127x_mode(hw, SX127X_STANDBY_MODE);
+	if (ret < 0) {
+		dev_err(&spi->dev, "%s: sx127x_mode() failed: %d\n", __func__, ret);
+		goto fail_begin;
+	}
+
+	ret = sx127x_begin_packet(hw);
+	if (ret < 0) {
+		dev_err(&spi->dev, "%s: sx127x_begin_packet() failed: %d\n", __func__, ret);
+		goto fail_begin;
+	}
+
+	ret = sx127x_write_buffer(hw, buffer, sizeof buffer);
+	if (ret < 0) {
+		dev_err(&spi->dev, "%s: sx127x_send() failed: %d\n", __func__, ret);
+		goto fail_begin;
+	}
+
+	ret = sx127x_end_packet(hw, 0);
+	if (ret < 0) {
+		dev_err(&spi->dev, "%s: sx127x_end_packet() failed: %d\n", __func__, ret);
+		goto fail_begin;
+	}*/
 
 fail_init:
 	ieee802154_free_hw(ieee);