Merge pull request #3349 from jflyper/bfdev-fix-dma-corruption-updated

F4 Fix UART TX DMA corruption

src/main/drivers/nvic.h

@@ -11,6 +11,7 @@
 #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_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)
 #define NVIC_PRIO_SERIALUART1_RXDMA        NVIC_BUILD_PRIORITY(1, 1)
 #define NVIC_PRIO_SERIALUART1              NVIC_BUILD_PRIORITY(1, 1)

src/main/drivers/serial_uart.c

@@ -28,10 +28,14 @@
 #include "platform.h"
 
 #include "build/build_config.h"
+#include "build/atomic.h"
 
 #include "common/utils.h"
+
+#include "drivers/dma.h"
 #include "drivers/gpio.h"
 #include "drivers/inverter.h"
+#include "drivers/nvic.h"
 #include "drivers/rcc.h"
 
 #include "drivers/serial.h"
@@ -52,10 +56,36 @@ void uartSetMode(serialPort_t *instance, portMode_t mode)
     uartReconfigure(uartPort);
 }
 
-void uartStartTxDMA(uartPort_t *s)
+void uartTryStartTxDMA(uartPort_t *s)
 {
+    // uartTryStartTxDMA must be protected, since it is called from
+    // uartWrite and handleUsartTxDma (an ISR).
+
+    ATOMIC_BLOCK(NVIC_PRIO_SERIALUART_TXDMA) {
 #ifdef STM32F4
-    DMA_Cmd(s->txDMAStream, DISABLE);
+        if (s->txDMAStream->CR & 1) {
+            // DMA is already in progress
+            return;
+        }
+
+        // For F4 (and F1), there are cases that NDTR (CNDTR for F1) is non-zero upon TC interrupt.
+        // We couldn't find out the root cause, so mask the case here.
+
+        if (s->txDMAStream->NDTR) {
+            // Possible premature TC case.
+            goto reenable;
+        }
+
+        // DMA_Cmd(s->txDMAStream, DISABLE); // XXX It's already disabled.
+
+        if (s->port.txBufferHead == s->port.txBufferTail) {
+            // No more data to transmit.
+            s->txDMAEmpty = true;
+            return;
+        }
+
+        // Start a new transaction.
+
         DMA_MemoryTargetConfig(s->txDMAStream, (uint32_t)&s->port.txBuffer[s->port.txBufferTail], DMA_Memory_0);
         //s->txDMAStream->M0AR = (uint32_t)&s->port.txBuffer[s->port.txBufferTail];
         if (s->port.txBufferHead > s->port.txBufferTail) {
@@ -67,8 +97,32 @@ void uartStartTxDMA(uartPort_t *s)
             s->port.txBufferTail = 0;
         }
         s->txDMAEmpty = false;
+
+    reenable:
         DMA_Cmd(s->txDMAStream, ENABLE);
 #else
+        if (s->txDMAChannel->CCR & 1) {
+            // DMA is already in progress
+            return;
+        }
+
+        // For F1 (and F4), there are cases that CNDTR (NDTR for F4) is non-zero upon TC interrupt.
+        // We couldn't find out the root cause, so mask the case here.
+        // F3 is not confirmed to be vulnerable, but not excluded as a safety.
+
+        if (s->txDMAChannel->CNDTR) {
+            // Possible premature TC case.
+            goto reenable;
+        }
+
+        if (s->port.txBufferHead == s->port.txBufferTail) {
+            // No more data to transmit.
+            s->txDMAEmpty = true;
+            return;
+        }
+
+        // Start a new transaction.
+
         s->txDMAChannel->CMAR = (uint32_t)&s->port.txBuffer[s->port.txBufferTail];
         if (s->port.txBufferHead > s->port.txBufferTail) {
             s->txDMAChannel->CNDTR = s->port.txBufferHead - s->port.txBufferTail;
@@ -78,8 +132,11 @@ void uartStartTxDMA(uartPort_t *s)
             s->port.txBufferTail = 0;
         }
         s->txDMAEmpty = false;
+
+    reenable:
         DMA_Cmd(s->txDMAChannel, ENABLE);
 #endif
+    }
 }
 
 uint32_t uartTotalRxBytesWaiting(const serialPort_t *instance)
@@ -198,13 +255,12 @@ void uartWrite(serialPort_t *instance, uint8_t ch)
     }
 
 #ifdef STM32F4
-    if (s->txDMAStream) {
-        if (!(s->txDMAStream->CR & 1))
+    if (s->txDMAStream)
 #else
-    if (s->txDMAChannel) {
-        if (!(s->txDMAChannel->CCR & 1))
+    if (s->txDMAChannel)
 #endif
-            uartStartTxDMA(s);
+    {
+        uartTryStartTxDMA(s); 
     } else {
         USART_ITConfig(s->USARTx, USART_IT_TXE, ENABLE);
     }

src/main/drivers/serial_uart_impl.h

@@ -161,7 +161,11 @@ extern uartDevice_t *uartDevmap[];
 
 extern const struct serialPortVTable uartVTable[];
 
+#ifdef USE_HAL_DRIVER
 void uartStartTxDMA(uartPort_t *s);
+#else
+void uartTryStartTxDMA(uartPort_t *s);
+#endif
 
 uartPort_t *serialUART(UARTDevice device, uint32_t baudRate, portMode_t mode, portOptions_t options);
 

src/main/drivers/serial_uart_stm32f10x.c

@@ -109,12 +109,9 @@ void uart_tx_dma_IRQHandler(dmaChannelDescriptor_t* descriptor)
 {
     uartPort_t *s = (uartPort_t*)(descriptor->userParam);
     DMA_CLEAR_FLAG(descriptor, DMA_IT_TCIF);
-    DMA_Cmd(descriptor->ref, DISABLE);
+    DMA_Cmd(descriptor->ref, DISABLE); // XXX F1 needs this!!!
 
-    if (s->port.txBufferHead != s->port.txBufferTail)
-        uartStartTxDMA(s);
-    else
-        s->txDMAEmpty = true;
+    uartTryStartTxDMA(s);
 }
 
 // XXX Should serialUART be consolidated?

src/main/drivers/serial_uart_stm32f30x.c

@@ -170,10 +170,7 @@ static void handleUsartTxDma(dmaChannelDescriptor_t* descriptor)
     DMA_CLEAR_FLAG(descriptor, DMA_IT_TCIF);
     DMA_Cmd(descriptor->ref, DISABLE);
 
-    if (s->port.txBufferHead != s->port.txBufferTail)
-        uartStartTxDMA(s);
-    else
-        s->txDMAEmpty = true;
+    uartTryStartTxDMA(s);
 }
 
 void serialUARTInitIO(IO_t txIO, IO_t rxIO, portMode_t mode, portOptions_t options, uint8_t af, uint8_t index)

src/main/drivers/serial_uart_stm32f4xx.c

@@ -166,12 +166,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 static void handleUsartTxDma(uartPort_t *s)
 {
-    DMA_Cmd(s->txDMAStream, DISABLE);
-
-    if (s->port.txBufferHead != s->port.txBufferTail)
-        uartStartTxDMA(s);
-    else
-        s->txDMAEmpty = true;
+    uartTryStartTxDMA(s);
 }
 
 void dmaIRQHandler(dmaChannelDescriptor_t* descriptor)

src/main/target/OMNIBUSF4/target.h

@@ -149,7 +149,6 @@
 #define USE_UART1
 #define UART1_RX_PIN            PA10
 #define UART1_TX_PIN            PA9
-#define UART1_AHB1_PERIPHERALS  RCC_AHB1Periph_DMA2
 
 #define USE_UART3
 #define UART3_RX_PIN            PB11