From 76756ee702c76f925b6c0e1c28d5695ce321c894 Mon Sep 17 00:00:00 2001
From: Maximilian Rozwora <maximilian.rozwora@iml.fraunhofer.de>
Date: Mon, 24 Feb 2025 14:34:41 +0100
Subject: [PATCH 1/3] fix: BufferedUartRx embedded_hal_nb::serial::Read impl

---
 embassy-stm32/src/usart/buffered.rs | 28 +++++++++-------------------
 1 file changed, 9 insertions(+), 19 deletions(-)

diff --git a/embassy-stm32/src/usart/buffered.rs b/embassy-stm32/src/usart/buffered.rs
index 7bbe01a00..3d8268de7 100644
--- a/embassy-stm32/src/usart/buffered.rs
+++ b/embassy-stm32/src/usart/buffered.rs
@@ -908,26 +908,16 @@ impl<'d> embedded_hal_02::serial::Read<u8> for BufferedUartRx<'d> {
     type Error = Error;
 
     fn read(&mut self) -> Result<u8, nb::Error<Self::Error>> {
-        let r = self.info.regs;
-        unsafe {
-            let sr = sr(r).read();
-            if sr.pe() {
-                rdr(r).read_volatile();
-                Err(nb::Error::Other(Error::Parity))
-            } else if sr.fe() {
-                rdr(r).read_volatile();
-                Err(nb::Error::Other(Error::Framing))
-            } else if sr.ne() {
-                rdr(r).read_volatile();
-                Err(nb::Error::Other(Error::Noise))
-            } else if sr.ore() {
-                rdr(r).read_volatile();
-                Err(nb::Error::Other(Error::Overrun))
-            } else if sr.rxne() {
-                Ok(rdr(r).read_volatile())
-            } else {
-                Err(nb::Error::WouldBlock)
+        let state = self.state;
+        let mut rx_reader = unsafe { state.rx_buf.reader() };
+        
+        if let Some(data) = rx_reader.pop_one() {
+            Ok(data)
+        } else {
+            if state.rx_buf.is_full() {
+                self.info.interrupt.pend();
             }
+            Err(nb::Error::WouldBlock)
         }
     }
 }

From c52f56785fbc4ad7feb7a0f61bd40f0d3563a845 Mon Sep 17 00:00:00 2001
From: Maximilian Rozwora <maximilian.rozwora@iml.fraunhofer.de>
Date: Mon, 24 Feb 2025 14:48:32 +0100
Subject: [PATCH 2/3] Apply cargo format

---
 embassy-stm32/src/usart/buffered.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/embassy-stm32/src/usart/buffered.rs b/embassy-stm32/src/usart/buffered.rs
index 3d8268de7..1cb9616d9 100644
--- a/embassy-stm32/src/usart/buffered.rs
+++ b/embassy-stm32/src/usart/buffered.rs
@@ -910,7 +910,7 @@ impl<'d> embedded_hal_02::serial::Read<u8> for BufferedUartRx<'d> {
     fn read(&mut self) -> Result<u8, nb::Error<Self::Error>> {
         let state = self.state;
         let mut rx_reader = unsafe { state.rx_buf.reader() };
-        
+
         if let Some(data) = rx_reader.pop_one() {
             Ok(data)
         } else {

From 519bd8646769899040b33a42ab57ddbd869d31ae Mon Sep 17 00:00:00 2001
From: Maximilian Rozwora <maximilian.rozwora@iml.fraunhofer.de>
Date: Mon, 24 Feb 2025 15:11:14 +0100
Subject: [PATCH 3/3] fix: Check buffer full before pop_done()

---
 embassy-stm32/src/usart/buffered.rs | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/embassy-stm32/src/usart/buffered.rs b/embassy-stm32/src/usart/buffered.rs
index 1cb9616d9..e61558b58 100644
--- 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)
         }
     }