From be881875917b93a8cdb7a4ab07876e1239fbe1be Mon Sep 17 00:00:00 2001
From: elagil <elagil@takanome.de>
Date: Mon, 25 Aug 2025 21:10:59 +0200
Subject: [PATCH] fix: transfer options

---
 embassy-stm32/src/dma/gpdma/mod.rs          | 3 +++
 embassy-stm32/src/dma/gpdma/ringbuffered.rs | 6 +++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/embassy-stm32/src/dma/gpdma/mod.rs b/embassy-stm32/src/dma/gpdma/mod.rs
index 1d2811ab4..b23c22dfb 100644
--- a/embassy-stm32/src/dma/gpdma/mod.rs
+++ b/embassy-stm32/src/dma/gpdma/mod.rs
@@ -283,6 +283,9 @@ impl AnyChannel {
         state.lli_state.transfer_count.store(0, Ordering::Relaxed)
     }
 
+    /// Configure a linked-list transfer.
+    ///
+    /// Transfer options apply only to the base register transfer, not the linked-list items.
     unsafe fn configure_linked_list<const ITEM_COUNT: usize>(
         &self,
         table: &Table<ITEM_COUNT>,
diff --git a/embassy-stm32/src/dma/gpdma/ringbuffered.rs b/embassy-stm32/src/dma/gpdma/ringbuffered.rs
index 6bd48258b..a5b127d08 100644
--- a/embassy-stm32/src/dma/gpdma/ringbuffered.rs
+++ b/embassy-stm32/src/dma/gpdma/ringbuffered.rs
@@ -69,6 +69,8 @@ pub struct ReadableRingBuffer<'a, W: Word> {
 
 impl<'a, W: Word> ReadableRingBuffer<'a, W> {
     /// Create a new ring buffer.
+    ///
+    /// Transfer options are applied to the individual linked list items.
     pub unsafe fn new(
         channel: impl Peripheral<P = impl Channel> + 'a,
         request: Request,
@@ -220,6 +222,8 @@ pub struct WritableRingBuffer<'a, W: Word> {
 
 impl<'a, W: Word> WritableRingBuffer<'a, W> {
     /// Create a new ring buffer.
+    ///
+    /// Transfer options are applied to the individual linked list items.
     pub unsafe fn new(
         channel: impl Peripheral<P = impl Channel> + 'a,
         request: Request,
@@ -279,7 +283,7 @@ impl<'a, W: Word> WritableRingBuffer<'a, W> {
             self.channel.configure_linked_list(
                 &self.table,
                 TransferOptions {
-                    half_transfer_ir: true,
+                    half_transfer_ir: false,
                     complete_transfer_ir: true,
                     ..Default::default()
                 },