Revert "cc2520: Rework reception logic"

This reverts commit bf77d902ac.

The commit is reverted because it causes hangs in packet
reception. After transferring data a while, the chip stops
packet reception.

Change-Id: Icb94e978e3ba526314afd5e80f35c877febe8740
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>

drivers/802.15.4/cc2520.c

@@ -54,12 +54,13 @@
 #include "cc2520.h"
 #include "cc2520_arch.h"
 
-#define CC2520_CONF_AUTOACK 1
+#ifndef CC2520_CONF_AUTOACK
+#define CC2520_CONF_AUTOACK 0
+#endif /* CC2520_CONF_AUTOACK */
+
 #define WITH_SEND_CCA 1
 
 #define FOOTER_LEN 2
-/* Len + FCF + SEQ + FCS + PAN ID */
-#define MIN_LENGTH_BEFORE_ACCEPT 10
 
 #define AUTOCRC (1 << 6)
 #define AUTOACK (1 << 5)
@@ -252,8 +253,6 @@ static inline void print_exceptions_1(void)
 		DBG("DPU_DONE_H");
 	}
 	DBG("\n");
-
-	setreg(CC2520_EXCFLAG1, 0);
 }
 
 static inline void print_errors(void)
@@ -283,7 +282,14 @@ static inline void print_errors(void)
 		DBG("RFBUFMOV_TIMEOUT");
 	}
 	DBG("\n");
+}
 
+static void clear_exceptions(void)
+{
+	DBG("Clearing up exceptions & errors\n");
+
+	setreg(CC2520_EXCFLAG0, 0);
+	setreg(CC2520_EXCFLAG1, 0);
 	setreg(CC2520_EXCFLAG2, 0);
 }
 
@@ -304,6 +310,7 @@ static void cc2520_print_gpio_config(void)
 #define print_exceptions_0()
 #define print_exceptions_1()
 #define print_errors()
+#define clear_exceptions()
 #define cc2520_print_gpio_config()
 #endif
 
@@ -482,6 +489,7 @@ static radio_result_t cc2520_set_rx_mode(radio_value_t value)
 	}
 	old_value = value;
 
+#if 1
 	if (receive_on) {
 		cc2520_strobe(CC2520_INS_SRXON);
 
@@ -490,6 +498,7 @@ static radio_result_t cc2520_set_rx_mode(radio_value_t value)
 			return RADIO_RESULT_ERROR;
 		}
 	}
+#endif /* 1/0 */
 
 	return RADIO_RESULT_OK;
 }
@@ -657,7 +666,7 @@ static int cc2520_transmit(struct net_buf *buf, unsigned short payload_len)
 		 */
 		BUSYWAIT_UNTIL(!(status() & BIT(CC2520_TX_ACTIVE)), WAIT_500ms);
 
-		DBG("Transmitted!\n");
+		DBG("status 0x%x\n", status());
 
 		if (!receive_on) {
 			/* We need to explicitly turn off the radio,
@@ -701,12 +710,18 @@ static int cc2520_prepare(const void *payload, unsigned short payload_len)
 
 	DBG("cc2520: sending %d bytes\n", payload_len);
 
+	clear_exceptions();
+
 	/* Write packet to TX FIFO. */
 	strobe(CC2520_INS_SFLUSHTX);
 
 	total_len = payload_len + FOOTER_LEN;
+	DBG("TX FIFO has %u bytes\n", getreg(CC2520_TXFIFOCNT));
 	cc2520_write_fifo_buf(&total_len, 1);
 	cc2520_write_fifo_buf(buf, payload_len);
+	DBG("TX FIFO has %u bytes\n", getreg(CC2520_TXFIFOCNT));
+
+	print_errors();
 
 	return 0;
 }
@@ -810,79 +825,65 @@ bool cc2520_set_pan_addr(unsigned pan, unsigned addr,
 	return true;
 }
 
-static inline uint8_t rxcount(void)
-{
-	return getreg(CC2520_RXFIFOCNT);
-}
-
 static int cc2520_read(void *buf, unsigned short bufsize)
 {
+	struct cc2520_config *info = cc2520_sgl_dev->config->config_info;
 	uint8_t footer[2];
-	uint8_t pkt_len;
 	uint8_t len;
-	uint8_t cnt;
 
 	if (!init_ok) {
 		return -EIO;
 	}
 
-	cnt = rxcount();
+	if (!cc2520_pending_packet()) {
-	if (cnt < MIN_LENGTH_BEFORE_ACCEPT) {
 		return -EAGAIN;
 	}
 
-	getrxbyte(&pkt_len);
-	len = pkt_len - FOOTER_LEN;
-
-	while (1) {
-		if (cnt > len) {
-			cnt = len;
-		}
-
-		getrxdata(buf, cnt);
-
-		buf += cnt;
-		len -= cnt;
-
-		if (len <= 0) {
-			break;
-		}
-
-		while (!(cnt = rxcount())) {
-		};
-	}
-
-	while (rxcount() < FOOTER_LEN) {
-	};
-
-	getrxdata(footer, FOOTER_LEN);
-	if (footer[1] & FOOTER1_CRC_OK) {
-		cc2520_last_rssi = footer[0];
-		cc2520_last_correlation = footer[1] & FOOTER1_CORRELATION;
-	} else {
-		DBG("RX: Bad CRC\n");
-		print_exceptions_0();
-		print_exceptions_1();
-
-		return -EINVAL;
-	}
-
-	if (cc2520_pending_packet()) {
-		/* Clean up in case of FIFO overflow!
-		 * This should not happen unless we were too slow to read
-		 * the previous packet. This is signaled by:
-		 * FIFOP = 1 and FIFO = 0
-		 */
-		if (!CC2520_FIFO_IS_1) {
-			DBG("RX: Overflow\n");
-			print_exceptions_0();
-			flushrx();
-		}
-	}
-
 	cc2520_packets_read++;
 
-	return pkt_len - FOOTER_LEN;
+	getrxbyte(&len);
+
+	DBG("%s: Incoming packet length: %d\n", __func__, len);
+
+	if ((len - FOOTER_LEN > bufsize) ||
+	    (len <= FOOTER_LEN)) {
+		goto error;
+	}
+
+	getrxdata(buf, len - FOOTER_LEN);
+	getrxdata(footer, FOOTER_LEN);
+
+	if (footer[1] & FOOTER1_CRC_OK) {
+		cc2520_last_rssi = footer[0];
+		cc2520_last_correlation = footer[1] & FOOTER1_CORRELATION;
+	} else {
+		goto error;
+	}
+
+	if (cc2520_pending_packet()) {
+		if (!CC2520_FIFO_IS_1) {
+			/* Clean up in case of FIFO overflow!  This happens
+			 * for every full length frame and is signaled by
+			 * FIFOP = 1 and FIFO = 0
+			 */
+			flushrx();
+		} else {
+			/* Another packet might be waiting
+			 * Let's unlock reading_packet_fiber()
+			 */
+			nano_fiber_sem_give(&info->read_lock);
+		}
+	}
+
+	return len - FOOTER_LEN;
+
+error:
+	print_exceptions_0();
+	print_exceptions_1();
+	print_errors();
+
+	flushrx();
+	return -EINVAL;
 }
 
 static void read_packet(void)
@@ -890,34 +891,35 @@ static void read_packet(void)
 	struct net_buf *buf;
 	int len;
 
-	do {
+	buf = l2_buf_get_reserve(0);
-		buf = l2_buf_get_reserve(0);
+	if (!buf) {
-		if (!buf) {
+		DBG("%s: Could not allocate buffer\n", __func__);
-			DBG("%s: Could not allocate buffer\n", __func__);
+		return;
-			break;
+	}
-		}
 
-		packetbuf_set_attr(buf, PACKETBUF_ATTR_TIMESTAMP,
+	packetbuf_set_attr(buf, PACKETBUF_ATTR_TIMESTAMP,
-				   last_packet_timestamp);
+			   last_packet_timestamp);
 
-		len = cc2520_read(packetbuf_dataptr(buf), PACKETBUF_SIZE);
+	len = cc2520_read(packetbuf_dataptr(buf), PACKETBUF_SIZE);
-		if (len < 0) {
+	if (len < 0) {
-			l2_buf_unref(buf);
+		goto out;
-			break;
+	}
-		}
 
-		packetbuf_set_attr(buf, PACKETBUF_ATTR_RSSI, cc2520_last_rssi);
+	packetbuf_set_attr(buf, PACKETBUF_ATTR_RSSI, cc2520_last_rssi);
-		packetbuf_set_attr(buf, PACKETBUF_ATTR_LINK_QUALITY,
+	packetbuf_set_attr(buf, PACKETBUF_ATTR_LINK_QUALITY,
-				   cc2520_last_correlation);
+			   cc2520_last_correlation);
-		packetbuf_set_datalen(buf, len);
+	packetbuf_set_datalen(buf, len);
 
-		if (net_driver_15_4_recv_from_hw(buf) < 0) {
+	DBG("%s: received %d bytes\n", __func__, len);
-			l2_buf_unref(buf);
-		}
 
-		last_packet_timestamp = cc2520_sfd_start_time;
+	if (net_driver_15_4_recv_from_hw(buf) < 0) {
-		cc2520_packets_seen++;
+		DBG("%s: rdc input failed, packet discarded\n", __func__);
-	} while (len > 0);
+		goto out;
+	}
+
+	return;
+out:
+	l2_buf_unref(buf);
 }
 
 /* Reading incoming packet, so through SPI, cannot be done directly
@@ -937,6 +939,9 @@ static void reading_packet_fiber(int unused1, int unused2)
 		read_packet();
 		cc2520_radio_unlock();
 
+		last_packet_timestamp = cc2520_sfd_start_time;
+		cc2520_packets_seen++;
+
 		net_analyze_stack("CC2520 Rx Fiber stack", cc2520_read_stack,
 				  CC2520_READING_STACK_SIZE);
 	}
@@ -946,6 +951,8 @@ static void cc2520_gpio_int_handler(struct device *port, uint32_t pin)
 {
 	struct cc2520_config *info = cc2520_sgl_dev->config->config_info;
 
+	DBG("%s: RX interrupt in pin %lu\n", __func__, pin);
+
 	/* In order to make this driver available for 2+ instances
 	 * it would require this handler to get access to the concerned
 	 * instance
@@ -1140,7 +1147,7 @@ static void cc2520_configure(struct device *dev)
 	/* Set auto CRC on frame. */
 #if CC2520_CONF_AUTOACK
 	setreg(CC2520_FRMCTRL0, AUTOCRC | AUTOACK);
-	setreg(CC2520_FRMFILT0, FRAME_MAX_VERSION | FRAME_FILTER_ENABLE);
+	setreg(CC2520_FRMFILT0, FRAME_MAX_VERSION|FRAME_FILTER_ENABLE);
 #else
 	/* setreg(CC2520_FRMCTRL0,    0x60); */
 	setreg(CC2520_FRMCTRL0, AUTOCRC);
@@ -1150,7 +1157,7 @@ static void cc2520_configure(struct device *dev)
 	/* SET_RXENMASK_ON_TX */
 	setreg(CC2520_FRMCTRL1, 1);
 	/* Set FIFOP threshold to maximum .*/
-	setreg(CC2520_FIFOPCTRL, FIFOP_THR(MIN_LENGTH_BEFORE_ACCEPT));
+	setreg(CC2520_FIFOPCTRL, FIFOP_THR(0x7F));
 
 	if (!cc2520_set_pan_addr(0xffff, 0x0000, NULL)) {
 		return;