fix: Check buffer full before pop_done()

Maximilian Rozwora · Maximilian Rozwora · commit 519bd8646769 · 2025-02-24T15:11:14.000+01:00
diff --git a/embassy-stm32/src/usart/buffered.rs b/embassy-stm32/src/usart/buffered.rs
@@ -911,12 +911,13 @@ impl<'d> embedded_hal_02::serial::Read<u8> for BufferedUartRx<'d> {
         let state = self.state;
         let mut rx_reader = unsafe { state.rx_buf.reader() };
 
+        let do_pend = state.rx_buf.is_full();
         if let Some(data) = rx_reader.pop_one() {
-            Ok(data)
-        } else {
-            if state.rx_buf.is_full() {
+            if do_pend {
                 self.info.interrupt.pend();
             }
+            Ok(data)
+        } else {
             Err(nb::Error::WouldBlock)
         }
     }

Original file line number	Diff line number	Diff line change
`@@ -911,12 +911,13 @@ impl<'d> embedded_hal_02::serial::Read<u8> for BufferedUartRx<'d> {`
`911`	`911`	`let state = self.state;`
`912`	`912`	`let mut rx_reader = unsafe { state.rx_buf.reader() };`
`913`	`913`
	`914`	`+ let do_pend = state.rx_buf.is_full();`
`914`	`915`	`if let Some(data) = rx_reader.pop_one() {`
`915`		`- Ok(data)`
`916`		`- } else {`
`917`		`- if state.rx_buf.is_full() {`
	`916`	`+ if do_pend {`
`918`	`917`	`self.info.interrupt.pend();`
`919`	`918`	`}`
	`919`	`+ Ok(data)`
	`920`	`+ } else {`
`920`	`921`	`Err(nb::Error::WouldBlock)`
`921`	`922`	`}`
`922`	`923`	`}`