1 files changed, 16 insertions, 3 deletions

diff --git a/embassy-usb/src/class/cdc_acm.rs b/embassy-usb/src/class/cdc_acm.rs
index 0a1a5e64f..ab2311f4e 100644
--- a/embassy-usb/src/class/cdc_acm.rs
+++ b/embassy-usb/src/class/cdc_acm.rs
@@ -1,7 +1,7 @@
 //! CDC-ACM class implementation, aka Serial over USB.
 
 use core::cell::{Cell, RefCell};
-use core::future::{poll_fn, Future};
+use core::future::{Future, poll_fn};
 use core::mem::{self, MaybeUninit};
 use core::sync::atomic::{AtomicBool, Ordering};
 use core::task::Poll;
@@ -366,6 +366,16 @@ impl<'d> ControlChanged<'d> {
     pub async fn control_changed(&self) {
         self.control.changed().await;
     }
+
+    /// Gets the DTR (data terminal ready) state
+    pub fn dtr(&self) -> bool {
+        self.control.dtr.load(Ordering::Relaxed)
+    }
+
+    /// Gets the RTS (request to send) state
+    pub fn rts(&self) -> bool {
+        self.control.rts.load(Ordering::Relaxed)
+    }
 }
 
 /// CDC ACM class packet sender.
@@ -545,9 +555,12 @@ impl<'d, D: Driver<'d>> embedded_io_async::Read for BufferedReceiver<'d, D> {
             return self.receiver.read_packet(buf).await;
         }
 
-        // Otherwise read a packet into the internal buffer, and return some of it to the caller
-        self.start = 0;
+        // Otherwise read a packet into the internal buffer, and return some of it to the caller.
+        //
+        // It's important that `start` and `end` be updated in this order so they're left in a
+        // consistent state if the `read` future is dropped mid-execution, e.g. from a timeout.
         self.end = self.receiver.read_packet(&mut self.buffer).await?;
+        self.start = 0;
         return Ok(self.read_from_buffer(buf));
     }
 }