Increment a sequence number when transceiver mode changes.

This is to ensure that a rapid change of e.g. RX->OFF->RX causes the
loop function for that mode to restart.

firmware/hackrf_usb/usb_api_sweep.c

@@ -87,6 +87,7 @@ usb_request_status_t usb_vendor_request_init_sweep(
 }
 
 void sweep_mode(void) {
+	uint32_t seq = transceiver_mode_seq();
 	unsigned int blocks_queued = 0;
 	unsigned int phase = 1;
 	bool odd = true;
@@ -97,7 +98,7 @@ void sweep_mode(void) {
 
 	baseband_streaming_enable(&sgpio_config);
 
-	while (TRANSCEIVER_MODE_RX_SWEEP == transceiver_mode()) {
+	while (transceiver_mode_seq() == seq) {
 		// Set up IN transfer of buffer 0.
 		if ( usb_bulk_buffer_offset >= 16384 && phase == 1) {
 			transfer = true;

firmware/hackrf_usb/usb_api_transceiver.c

@@ -237,6 +237,7 @@ usb_request_status_t usb_vendor_request_set_freq_explicit(
 }
 
 static volatile transceiver_mode_t _transceiver_mode = TRANSCEIVER_MODE_OFF;
+static volatile uint32_t _transceiver_mode_seq = 0;
 static volatile hw_sync_mode_t _hw_sync_mode = HW_SYNC_MODE_OFF;
 
 void set_hw_sync_mode(const hw_sync_mode_t new_hw_sync_mode) {
@@ -247,6 +248,10 @@ transceiver_mode_t transceiver_mode(void) {
 	return _transceiver_mode;
 }
 
+uint32_t transceiver_mode_seq(void) {
+	return _transceiver_mode_seq;
+}
+
 void set_transceiver_mode(const transceiver_mode_t new_transceiver_mode) {
 	baseband_streaming_disable(&sgpio_config);
 	operacake_sctimer_reset_state();
@@ -286,6 +291,8 @@ void set_transceiver_mode(const transceiver_mode_t new_transceiver_mode) {
 
 		usb_bulk_buffer_offset = 0;
 	}
+
+	_transceiver_mode_seq++;
 }
 
 usb_request_status_t usb_vendor_request_set_transceiver_mode(
@@ -324,11 +331,12 @@ usb_request_status_t usb_vendor_request_set_hw_sync_mode(
 }
 
 void rx_mode(void) {
+	uint32_t seq = _transceiver_mode_seq;
 	unsigned int phase = 1;
 
 	baseband_streaming_enable(&sgpio_config);
 
-	while (TRANSCEIVER_MODE_RX == _transceiver_mode) {
+	while (_transceiver_mode_seq == seq) {
 		// Set up IN transfer of buffer 0.
 		if (16384 <= usb_bulk_buffer_offset && 1 == phase) {
 			usb_transfer_schedule_block(
@@ -353,6 +361,7 @@ void rx_mode(void) {
 }
 
 void tx_mode(void) {
+	uint32_t seq = _transceiver_mode_seq;
 	unsigned int phase = 1;
 
 	memset(&usb_bulk_buffer[0x0000], 0, 0x8000);
@@ -366,7 +375,7 @@ void tx_mode(void) {
 	// Start transmitting zeros while the host fills buffer 1.
 	baseband_streaming_enable(&sgpio_config);
 
-	while (TRANSCEIVER_MODE_TX == _transceiver_mode) {
+	while (_transceiver_mode_seq == seq) {
 		// Set up OUT transfer of buffer 0.
 		if (16384 <= usb_bulk_buffer_offset && 1 == phase) {
 			usb_transfer_schedule_block(

firmware/hackrf_usb/usb_api_transceiver.h

@@ -57,6 +57,7 @@ usb_request_status_t usb_vendor_request_set_hw_sync_mode(
 	usb_endpoint_t* const endpoint,	const usb_transfer_stage_t stage);
 
 transceiver_mode_t transceiver_mode(void);
+uint32_t transceiver_mode_seq(void);
 void set_transceiver_mode(const transceiver_mode_t new_transceiver_mode);
 void start_streaming_on_hw_sync();
 void rx_mode(void);