From 3e7de3a5d81e32e77aeb5232e5a7f512ce39db0e Mon Sep 17 00:00:00 2001
From: James Munns <james@onevariable.com>
Date: Tue, 9 Dec 2025 17:53:45 +0100
Subject: Change transfer to return a result

---
 embassy-mcxa/src/dma.rs                             | 14 +++++++++-----
 examples/mcxa/src/bin/dma_mem_to_mem.rs             |  2 +-
 examples/mcxa/src/bin/raw_dma_ping_pong_transfer.rs |  2 +-
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/embassy-mcxa/src/dma.rs b/embassy-mcxa/src/dma.rs
index ff9ebeb05..ffe816469 100644
--- a/embassy-mcxa/src/dma.rs
+++ b/embassy-mcxa/src/dma.rs
@@ -773,10 +773,14 @@ impl<C: Channel> DmaChannel<C> {
     ///
     /// The source and destination buffers must remain valid for the
     /// duration of the transfer.
-    pub fn mem_to_mem<W: Word>(&self, src: &[W], dst: &mut [W], options: TransferOptions) -> Transfer<'_> {
-        assert!(!src.is_empty());
-        assert!(dst.len() >= src.len());
-        assert!(src.len() <= 0x7fff);
+    pub fn mem_to_mem<W: Word>(&self, src: &[W], dst: &mut [W], options: TransferOptions) -> Result<Transfer<'_>, Error> {
+        let mut invalid = false;
+        invalid |= src.is_empty();
+        invalid |= src.len() > dst.len();
+        invalid |= src.len() > 0x7fff;
+        if invalid {
+            return Err(Error::Configuration);
+        }
 
         let size = W::size();
         let byte_count = (src.len() * size.bytes()) as u32;
@@ -837,7 +841,7 @@ impl<C: Channel> DmaChannel<C> {
                 .set_bit() // Start the channel
         });
 
-        Transfer::new(self.as_any())
+        Ok(Transfer::new(self.as_any()))
     }
 
     /// Fill a memory buffer with a pattern value (memset).
diff --git a/examples/mcxa/src/bin/dma_mem_to_mem.rs b/examples/mcxa/src/bin/dma_mem_to_mem.rs
index b20068b79..a9ee9ffdf 100644
--- a/examples/mcxa/src/bin/dma_mem_to_mem.rs
+++ b/examples/mcxa/src/bin/dma_mem_to_mem.rs
@@ -70,7 +70,7 @@ async fn main(_spawner: Spawner) {
 
     // Perform type-safe memory-to-memory transfer using Embassy-style async API
     // Using async `.await` - the executor can run other tasks while waiting!
-    let transfer = dma_ch0.mem_to_mem(src, dst, options);
+    let transfer = dma_ch0.mem_to_mem(src, dst, options).unwrap();
     transfer.await;
 
     defmt::info!("DMA mem-to-mem transfer complete!");
diff --git a/examples/mcxa/src/bin/raw_dma_ping_pong_transfer.rs b/examples/mcxa/src/bin/raw_dma_ping_pong_transfer.rs
index 51a7bc275..1e16e60ba 100644
--- a/examples/mcxa/src/bin/raw_dma_ping_pong_transfer.rs
+++ b/examples/mcxa/src/bin/raw_dma_ping_pong_transfer.rs
@@ -217,7 +217,7 @@ async fn main(_spawner: Spawner) {
     defmt::info!("Starting transfer with half_transfer_interrupt...");
 
     // Create the transfer
-    let mut transfer = dma_ch1.mem_to_mem(src2, dst2, options);
+    let mut transfer = dma_ch1.mem_to_mem(src2, dst2, options).unwrap();
 
     // Wait for half-transfer (first 4 elements)
     defmt::info!("Waiting for first half...");
-- 
cgit