Merge pull request #11350 from hydra/bf-fix-elrs-link-failures

Fix ELRS link failures where link is unrecoverable.

src/main/drivers/nvic.h

@@ -30,6 +30,7 @@
 #define NVIC_PRIO_TRANSPONDER_DMA          NVIC_BUILD_PRIORITY(3, 0)
 #define NVIC_PRIO_MPU_INT_EXTI             NVIC_BUILD_PRIORITY(0x0f, 0x0f)
 #define NVIC_PRIO_MAG_INT_EXTI             NVIC_BUILD_PRIORITY(0x0f, 0x0f)
+#define NVIC_PRIO_RX_SPI_INT_EXTI          NVIC_BUILD_PRIORITY(0x0f, 0x0f)
 #define NVIC_PRIO_WS2811_DMA               NVIC_BUILD_PRIORITY(1, 2)  // TODO - is there some reason to use high priority? (or to use DMA IRQ at all?)
 #define NVIC_PRIO_SERIALUART_TXDMA         NVIC_BUILD_PRIORITY(1, 1)  // Highest of all SERIALUARTx_TXDMA
 #define NVIC_PRIO_SERIALUART1_TXDMA        NVIC_BUILD_PRIORITY(1, 1)

src/main/drivers/rx/rx_spi.c

@@ -125,7 +125,7 @@ void rxSpiExtiInit(ioConfig_t rxSpiExtiPinConfig, extiTrigger_t rxSpiExtiPinTrig
             extiLevel = false;
         }
         EXTIHandlerInit(&rxSpiExtiCallbackRec, rxSpiExtiHandler);
-        EXTIConfig(extiPin, &rxSpiExtiCallbackRec, NVIC_PRIO_MPU_INT_EXTI, rxSpiExtiPinConfig, rxSpiExtiPinTrigger);
+        EXTIConfig(extiPin, &rxSpiExtiCallbackRec, NVIC_PRIO_RX_SPI_INT_EXTI, rxSpiExtiPinConfig, rxSpiExtiPinTrigger);
         EXTIEnable(extiPin, true);
     }
 }

src/main/drivers/rx/rx_sx127x.c

@@ -31,9 +31,12 @@
 
 #ifdef USE_RX_SX127X
 
+#include "build/atomic.h"
+
 #include "drivers/bus_spi.h"
 #include "drivers/io.h"
 #include "drivers/io_impl.h"
+#include "drivers/nvic.h"
 #include "drivers/rx/rx_sx127x.h"
 #include "drivers/rx/rx_spi.h"
 #include "drivers/time.h"
@@ -73,15 +76,23 @@ static bool sx127xDetectChip(void)
 
 uint8_t sx127xISR(timeUs_t *timeStamp)
 {
-    if (rxSpiPollExti()) {
+    bool extiTriggered = false;
-        if (rxSpiGetLastExtiTimeUs()) {
+    timeUs_t extiTimestamp;
-            *timeStamp = rxSpiGetLastExtiTimeUs();
+
+    ATOMIC_BLOCK(NVIC_PRIO_RX_SPI_INT_EXTI) {
+        // prevent a data-race that can occur if a new EXTI ISR occurs during this block.
+        extiTriggered = rxSpiPollExti();
+        extiTimestamp = rxSpiGetLastExtiTimeUs();
+        if (extiTriggered) {
+            rxSpiResetExti();
+        }
     }
 
-        uint8_t irqReason;
+    if (extiTriggered) {
-        irqReason = sx127xGetIrqReason();
+        uint8_t irqReason = sx127xGetIrqReason();
-
+        if (extiTimestamp) {
-        rxSpiResetExti();
+            *timeStamp = extiTimestamp;
+        }
 
         return irqReason;
     }
@@ -445,7 +456,9 @@ uint8_t sx127xGetIrqReason(void)
 {
     uint8_t irqFlags = sx127xGetIrqFlags();
     sx127xClearIrqFlags();
-    if ((irqFlags & SX127X_CLEAR_IRQ_FLAG_TX_DONE)) {
+    if ((irqFlags & SX127X_CLEAR_IRQ_FLAG_TX_DONE) && (irqFlags & SX127X_CLEAR_IRQ_FLAG_RX_DONE)) {
+        return 3;
+    } else if ((irqFlags & SX127X_CLEAR_IRQ_FLAG_TX_DONE)) {
         return 2;
     } else if ((irqFlags & SX127X_CLEAR_IRQ_FLAG_RX_DONE)) {
         return 1;

src/main/drivers/rx/rx_sx1280.c

@@ -32,9 +32,12 @@
 
 #ifdef USE_RX_SX1280
 
+#include "build/atomic.h"
+
 #include "drivers/bus_spi.h"
 #include "drivers/io.h"
 #include "drivers/io_impl.h"
+#include "drivers/nvic.h"
 #include "drivers/rx/rx_sx1280.h"
 #include "drivers/rx/rx_spi.h"
 #include "drivers/time.h"
@@ -103,16 +106,23 @@ bool sx1280Init(IO_t resetPin, IO_t busyPin)
 
 uint8_t sx1280ISR(timeUs_t *timeStamp)
 {
-    if (rxSpiPollExti()) {
+    bool extiTriggered = false;
-        if (rxSpiGetLastExtiTimeUs()) {
+    timeUs_t extiTimestamp;
-            *timeStamp = rxSpiGetLastExtiTimeUs();
+
+    ATOMIC_BLOCK(NVIC_PRIO_RX_SPI_INT_EXTI) {
+        // prevent a data-race that can occur if a new EXTI ISR occurs during this block.
+        extiTriggered = rxSpiPollExti();
+        extiTimestamp = rxSpiGetLastExtiTimeUs();
+        if (extiTriggered) {
+            rxSpiResetExti();
+        }
     }
 
-        uint8_t irqReason;
+    if (extiTriggered) {
-        irqReason = sx1280GetIrqReason();
+        uint8_t irqReason = sx1280GetIrqReason();
-
+        if (extiTimestamp) {
-        rxSpiResetExti();
+            *timeStamp = extiTimestamp;
-
+        }
         return irqReason;
     }
     return 0;
@@ -418,8 +428,11 @@ void sx1280ClearIrqStatus(const uint16_t irqMask)
 uint8_t sx1280GetIrqReason(void)
 {
     uint16_t irqStatus = sx1280GetIrqStatus();
+
     sx1280ClearIrqStatus(SX1280_IRQ_RADIO_ALL);
-    if ((irqStatus & SX1280_IRQ_TX_DONE)) {
+    if ((irqStatus & SX1280_IRQ_TX_DONE) && (irqStatus & SX1280_IRQ_RX_DONE)) {
+        return 3;
+    } else if ((irqStatus & SX1280_IRQ_TX_DONE)) {
         return 2;
     } else if ((irqStatus & SX1280_IRQ_RX_DONE)) {
         return 1;

src/main/rx/expresslrs.c

@@ -1073,7 +1073,9 @@ rx_spi_received_e expressLrsDataReceived(uint8_t *payload)
     }
 
     uint8_t irqReason = receiver.rxISR(&isrTimeStampUs);
-    if (irqReason == ELRS_DIO_TX_DONE) {
+    if (irqReason == ELRS_DIO_RX_AND_TX_DONE) {
+        startReceiving();
+    } else if (irqReason == ELRS_DIO_TX_DONE) {
         startReceiving();
     } else if (irqReason == ELRS_DIO_RX_DONE) {
         result = processRFPacket(payload, isrTimeStampUs);

src/main/rx/expresslrs_impl.h

@@ -33,7 +33,8 @@ typedef enum {
 typedef enum {
     ELRS_DIO_UNKNOWN = 0,
     ELRS_DIO_RX_DONE = 1,
-    ELRS_DIO_TX_DONE = 2
+    ELRS_DIO_TX_DONE = 2,
+    ELRS_DIO_RX_AND_TX_DONE = 3,
 } dioReason_e;
 
 typedef enum {