stm32/spi: fix blocking transfer hanging after async.

2 files changed, 20 insertions, 0 deletions

diff --git a/embassy-stm32/src/spi/mod.rs b/embassy-stm32/src/spi/mod.rs
index a743a036c..764a967ca 100644
--- a/embassy-stm32/src/spi/mod.rs
+++ b/embassy-stm32/src/spi/mod.rs
@@ -575,6 +575,7 @@ impl<'d, T: Instance, Tx, Rx> Spi<'d, T, Tx, Rx> {
     }
 
     pub fn blocking_write<W: Word>(&mut self, words: &[W]) -> Result<(), Error> {
+        unsafe { T::REGS.cr1().modify(|w| w.set_spe(true)) }
         flush_rx_fifo(T::REGS);
         self.set_word_size(W::WORDSIZE);
         for word in words.iter() {
@@ -584,6 +585,7 @@ impl<'d, T: Instance, Tx, Rx> Spi<'d, T, Tx, Rx> {
     }
 
     pub fn blocking_read<W: Word>(&mut self, words: &mut [W]) -> Result<(), Error> {
+        unsafe { T::REGS.cr1().modify(|w| w.set_spe(true)) }
         flush_rx_fifo(T::REGS);
         self.set_word_size(W::WORDSIZE);
         for word in words.iter_mut() {
@@ -593,6 +595,7 @@ impl<'d, T: Instance, Tx, Rx> Spi<'d, T, Tx, Rx> {
     }
 
     pub fn blocking_transfer_in_place<W: Word>(&mut self, words: &mut [W]) -> Result<(), Error> {
+        unsafe { T::REGS.cr1().modify(|w| w.set_spe(true)) }
         flush_rx_fifo(T::REGS);
         self.set_word_size(W::WORDSIZE);
         for word in words.iter_mut() {
@@ -602,6 +605,7 @@ impl<'d, T: Instance, Tx, Rx> Spi<'d, T, Tx, Rx> {
     }
 
     pub fn blocking_transfer<W: Word>(&mut self, read: &mut [W], write: &[W]) -> Result<(), Error> {
+        unsafe { T::REGS.cr1().modify(|w| w.set_spe(true)) }
         flush_rx_fifo(T::REGS);
         self.set_word_size(W::WORDSIZE);
         let len = read.len().max(write.len());
diff --git a/tests/stm32/src/bin/spi_dma.rs b/tests/stm32/src/bin/spi_dma.rs
index 3e9521ae7..f4f1994c0 100644
--- a/tests/stm32/src/bin/spi_dma.rs
+++ b/tests/stm32/src/bin/spi_dma.rs
@@ -68,6 +68,22 @@ async fn main(_spawner: Spawner, p: Peripherals) {
     spi.read::<u8>(&mut []).await.unwrap();
     spi.write::<u8>(&[]).await.unwrap();
 
+    // === Check mixing blocking with async.
+    spi.blocking_transfer(&mut buf, &data).unwrap();
+    assert_eq!(buf, data);
+    spi.transfer(&mut buf, &data).await.unwrap();
+    assert_eq!(buf, data);
+    spi.blocking_write(&buf).unwrap();
+    spi.transfer(&mut buf, &data).await.unwrap();
+    assert_eq!(buf, data);
+    spi.blocking_read(&mut buf).unwrap();
+    spi.blocking_write(&buf).unwrap();
+    spi.write(&buf).await.unwrap();
+    spi.read(&mut buf).await.unwrap();
+    spi.blocking_write(&buf).unwrap();
+    spi.blocking_read(&mut buf).unwrap();
+    spi.write(&buf).await.unwrap();
+
     info!("Test OK");
     cortex_m::asm::bkpt();
 }