fixed: #3900 #4452 #4689 stm32 Uart::read_until_idle()

embassy-stm32/CHANGELOG.md

@@ -7,7 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 <!-- next-header -->
 ## Unreleased - ReleaseDate
-
+- add: Added read_until_idle() example for stm32u5
+- fix: Fixed stm32 Uart::read_until_idle() bug in [#3900] [#4452] [#4689]
 - fix: Fixed STM32H5 builds requiring time feature
 - feat: Derive Clone, Copy for QSPI Config
 - fix: stm32/i2c in master mode (blocking): subsequent transmissions failed after a NACK was received

embassy-stm32/src/usart/mod.rs

@@ -876,9 +876,12 @@ impl<'d> UartRx<'d, Async> {
             Either::Left(((), _)) => Ok(ReadCompletionEvent::DmaCompleted),
 
             // Idle line detected first
-            Either::Right((Ok(()), transfer)) => Ok(ReadCompletionEvent::Idle(
-                buffer_len - transfer.get_remaining_transfers() as usize,
-            )),
+            Either::Right((Ok(()), mut transfer)) => {
+                transfer.request_pause();
+                Ok(ReadCompletionEvent::Idle(
+                    buffer_len - transfer.get_remaining_transfers() as usize,
+                ))
+            }
 
             // error occurred
             Either::Right((Err(e), _)) => Err(e),

examples/stm32u5/src/bin/uart.rs

@@ -0,0 +1,27 @@
+#![no_std]
+#![no_main]
+
+use defmt::*;
+use embassy_executor::Spawner;
+use embassy_stm32::usart::{self, Config, Uart};
+use embassy_stm32::{bind_interrupts, peripherals};
+use {defmt_rtt as _, panic_probe as _};
+
+bind_interrupts!(struct Irqs{
+    USART1 => usart::InterruptHandler<peripherals::USART1>;
+});
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) -> ! {
+    let p = embassy_stm32::init(Default::default());
+    info!("Hello World!");
+    let config = Config::default();
+    let mut uart = Uart::new(p.USART1, p.PA10, p.PA9, Irqs, p.GPDMA1_CH0, p.GPDMA1_CH1, config).unwrap();
+    let mut buffer = [0u8; 32];
+    loop {
+        if let Ok(len) = uart.read_until_idle(&mut buffer).await {
+            info!("{}", &buffer[0..len]);
+            uart.write(&buffer[0..len]).await.unwrap()
+        }
+    }
+}