Fix UART buffering, now it works

1 files changed, 8 insertions, 7 deletions

diff --git a/app/platform/stm32f0-gcc/uart.cpp b/app/platform/stm32f0-gcc/uart.cpp
index 4d9bf5f..89472ee 100644
--- a/app/platform/stm32f0-gcc/uart.cpp
+++ b/app/platform/stm32f0-gcc/uart.cpp
@@ -42,7 +42,7 @@ UART g_uart4{
     RingBuffer<uint8_t>(g_uart4_tx_buffer, kUART4TxBufferSize),
 };
 
-static constexpr Min(size_t a, size_t b) { return (a >= b) ? a : b; }
+static constexpr Min(size_t a, size_t b) { return (a <= b) ? a : b; }
 
 size_t UARTWrite(UART* uart, const void *buf, size_t nbytes)
 {
@@ -96,19 +96,20 @@ void UARTHandleInterrupt(UART* uart)
         return;
     for (int _ = 0; _ < 256; _++) {
         const uint32_t isr = usart_regs->ISR;
-        const bool rxne = isr & USART_ISR_RXNE;
-        const bool txe = isr & USART_ISR_TXE;
-        if (!rxne && !txe)
-            break;
-        if (rxne) {
+        bool done = true;
+        if (isr & USART_ISR_RXNE) {
             uart->rx_buffer.Push(usart_regs->RDR);
+            done = false;
         }
-        if (txe) {
+        if (isr & USART_ISR_TXE) {
             if (!uart->tx_buffer.IsEmpty()) {
                 usart_regs->TDR = uart->tx_buffer.Pop();
+                done = false;
             } else {
                 usart_regs->CR1 &= ~USART_CR1_TXEIE;
             }
         }
+        if (done)
+            break;
     }
 }