Merge pull request 'more SPI improvements' (#28) from spi-tweaks into main

Reviewed-on: #28

va108xx/examples/embassy/Cargo.toml

@@ -4,8 +4,9 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-cfg-if = "1"
+cortex-m = { version = "0.7", features = ["critical-section-single-core"] }
 cortex-m-rt = "0.7"
+cfg-if = "1"
 embedded-hal-async = "1"
 embedded-io = "0.7"
 embedded-io-async = "0.7"
@@ -18,10 +19,10 @@ panic-probe = { version = "1", features = ["print-defmt"] }
 
 critical-section = "1"
 
-embassy-sync = "0.7"
+embassy-sync = "0.8"
 embassy-time = "0.5"
-embassy-executor = { version = "0.9", features = [
-  "arch-cortex-m",
+embassy-executor = { version = "0.10", features = [
+  "platform-cortex-m",
   "executor-thread",
   "executor-interrupt"
 ]}

va108xx/examples/embassy/src/bin/async-gpio.rs

@@ -62,6 +62,9 @@ async fn main(spawner: Spawner) {
 
     // Safety: Only called once here.
     va108xx_embassy::init(dp.tim23, dp.tim22, SYSCLK_FREQ);
+    unsafe {
+        cortex_m::interrupt::enable();
+    }
 
     let porta = PinsA::new(dp.porta);
     let portb = PinsB::new(dp.portb);
@@ -71,36 +74,35 @@ async fn main(spawner: Spawner) {
     let out_pb22 = Output::new(portb.pb22, PinState::Low);
     let in_pb23 = Input::new_floating(portb.pb23);
 
-    let mut in_pa1_async = InputPinAsync::new(in_pa1, pac::Interrupt::OC10);
-    let mut in_pb23_async = InputPinAsync::new(in_pb23, PB22_TO_PB23_IRQ);
+    let mut in_pa1_async = InputPinAsync::new(
+        in_pa1,
+        va108xx_hal::InterruptConfig::new(pac::Interrupt::OC10, true, true),
+    );
+    let mut in_pb23_async = InputPinAsync::new(
+        in_pb23,
+        va108xx_hal::InterruptConfig::new(PB22_TO_PB23_IRQ, true, true),
+    );
 
-    spawner
-        .spawn(output_task(
-            "PA0 to PA1",
-            out_pa0,
-            CHANNEL_PA0_PA1.receiver(),
-        ))
-        .unwrap();
-    spawner
-        .spawn(output_task(
-            "PB22 to PB23",
-            out_pb22,
-            CHANNEL_PB22_TO_PB23.receiver(),
-        ))
-        .unwrap();
+    spawner.spawn(output_task("PA0 to PA1", out_pa0, CHANNEL_PA0_PA1.receiver()).unwrap());
+    spawner.spawn(output_task("PB22 to PB23", out_pb22, CHANNEL_PB22_TO_PB23.receiver()).unwrap());
 
-    if CHECK_PA0_TO_PA1 {
-        check_pin_to_pin_async_ops("PA0 to PA1", CHANNEL_PA0_PA1.sender(), &mut in_pa1_async).await;
-        defmt::info!("Example PA0 to PA1 done");
-    }
-    if CHECK_PB22_TO_PB23 {
-        check_pin_to_pin_async_ops(
-            "PB22 to PB23",
-            CHANNEL_PB22_TO_PB23.sender(),
-            &mut in_pb23_async,
-        )
-        .await;
-        defmt::info!("Example PB22 to PB23 done");
+    for i in 0..3 {
+        defmt::info!("Starting async GPIO operations check {}", i);
+        if CHECK_PA0_TO_PA1 {
+            check_pin_to_pin_async_ops("PA0 to PA1", CHANNEL_PA0_PA1.sender(), &mut in_pa1_async)
+                .await;
+            defmt::info!("Example PA0 to PA1 done");
+        }
+        if CHECK_PB22_TO_PB23 {
+            check_pin_to_pin_async_ops(
+                "PB22 to PB23",
+                CHANNEL_PB22_TO_PB23.sender(),
+                &mut in_pb23_async,
+            )
+            .await;
+            defmt::info!("Example PB22 to PB23 done");
+        }
+        Timer::after(Duration::from_millis(500)).await;
     }
 
     defmt::info!("Example done, toggling LED0");

va108xx/examples/embassy/src/bin/async-uart-rx.rs

@@ -97,9 +97,7 @@ async fn main(spawner: Spawner) {
     });
     let mut async_rx_uart_a = RxAsync::new(rx_uart_a, cons_uart_a);
     let async_rx_uart_b = RxAsyncOverwriting::new(rx_uart_b, &CONSUMER_UART_B);
-    spawner
-        .spawn(uart_b_task(async_rx_uart_b, tx_uart_b))
-        .unwrap();
+    spawner.spawn(uart_b_task(async_rx_uart_b, tx_uart_b).unwrap());
     let mut buf = [0u8; 256];
     loop {
         defmt::info!("Current time UART A: {}", Instant::now().as_secs());

va108xx/vorago-reb1/src/button.rs

@@ -36,7 +36,7 @@ impl Button {
         irq_cfg: InterruptConfig,
     ) {
         self.0.configure_edge_interrupt(edge_type);
-        self.0.enable_interrupt(irq_cfg);
+        self.0.enable_interrupt(irq_cfg, true);
     }
 
     /// Configures an IRQ on level.
@@ -46,7 +46,7 @@ impl Button {
         irq_cfg: InterruptConfig,
     ) {
         self.0.configure_level_interrupt(level);
-        self.0.enable_interrupt(irq_cfg);
+        self.0.enable_interrupt(irq_cfg, true);
     }
 
     /// Configures a filter on the button. This can be useful for debouncing the switch.

vorago-shared-hal/CHANGELOG.md

@@ -30,6 +30,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Added missing `AnyPin` trait impl for Multi HW CS pins.
 - Expose inner `Input` pin for `InputPinAsync`.
 - Bugfix for UART clock calculation with 8x baud mode.
+- Possible bugfix for Asynch GPIO where the interrupt handler could become stuck in a loop.
+- Robustness improvements for the Asynch GPIO driver code.
 
 ## [v0.2.0] 2025-09-03
 

vorago-shared-hal/Cargo.toml

@@ -29,7 +29,7 @@ fugit = "0.3"
 defmt = { version = "1", optional = true }
 va108xx = { version = "0.6", path = "../va108xx/va108xx", default-features = false, optional = true }
 va416xx = { version = "0.5", path = "../va416xx/va416xx", default-features = false, optional = true }
-embassy-sync = "0.7"
+embassy-sync = "0.8"
 embassy-time-driver = "0.2"
 embassy-time-queue-utils = "0.3"
 once_cell = { version = "1", default-features = false, features = [

vorago-shared-hal/src/gpio/asynch.rs

@@ -21,9 +21,6 @@ use crate::{InterruptConfig, NUM_PORT_A, NUM_PORT_B};
 #[cfg(feature = "vor4x")]
 use super::ll::PortDoesNotSupportInterrupts;
 
-#[cfg(feature = "vor1x")]
-use va108xx as pac;
-
 pub use super::ll::InterruptEdge;
 use super::{
     Input, Port,
@@ -118,7 +115,7 @@ pub fn on_interrupt_for_async_gpio_for_port(
 }
 
 fn on_interrupt_for_async_gpio_for_port_generic(port: Port) {
-    let gpio = unsafe { port.steal_gpio() };
+    let mut gpio = unsafe { port.steal_regs() };
 
     let irq_enb = gpio.read_irq_enable();
     let edge_status = gpio.read_edge_status();
@@ -134,18 +131,19 @@ fn on_interrupt_for_port(
     wakers: &'static [AtomicWaker],
     edge_detection: &'static [AtomicBool],
 ) {
+    // Check all enabled interrupts.
     while irq_enb != 0 {
+        // For all enabled interrupts, check whether the corresponding edge detection has
+        // triggered.
         let bit_pos = irq_enb.trailing_zeros() as usize;
         let bit_mask = 1 << bit_pos;
 
-        wakers[bit_pos].wake();
-
         if edge_status & bit_mask != 0 {
             edge_detection[bit_pos].store(true, core::sync::atomic::Ordering::Relaxed);
-
-            // Clear the processed bit
-            irq_enb &= !bit_mask;
+            wakers[bit_pos].wake();
         }
+        // Clear the processed bit
+        irq_enb &= !bit_mask;
     }
 }
 
@@ -163,13 +161,12 @@ pub struct InputPinFuture {
 impl InputPinFuture {
     /// Create a new input pin future from mutable reference to an [Input] pin.
     #[cfg(feature = "vor1x")]
-    pub fn new_with_input_pin(pin: &mut Input, irq: pac::Interrupt, edge: InterruptEdge) -> Self {
+    pub fn new_with_input_pin(pin: &mut Input, edge: InterruptEdge) -> Self {
         let (waker_group, edge_detection_group) =
             pin_group_to_waker_and_edge_detection_group(pin.id().port());
         edge_detection_group[pin.id().offset()].store(false, core::sync::atomic::Ordering::Relaxed);
         pin.configure_edge_interrupt(edge);
-        #[cfg(feature = "vor1x")]
-        pin.enable_interrupt(InterruptConfig::new(irq, true, true));
+        pin.enable_interrupt_gpio_only();
         Self {
             id: pin.id(),
             waker_group,
@@ -186,7 +183,7 @@ impl InputPinFuture {
         let (waker_group, edge_detection_group) =
             pin_group_to_waker_and_edge_detection_group(pin.id().port());
         pin.configure_edge_interrupt(edge);
-        pin.enable_interrupt(true)?;
+        pin.enable_interrupt_gpio_only();
         Ok(Self {
             id: pin.id(),
             waker_group,
@@ -223,8 +220,6 @@ impl Future for InputPinFuture {
 /// Input pin which has additional asynchronous support.
 pub struct InputPinAsync {
     pin: Input,
-    #[cfg(feature = "vor1x")]
-    irq: va108xx::Interrupt,
 }
 
 impl InputPinAsync {
@@ -235,8 +230,10 @@ impl InputPinAsync {
     /// generic [on_interrupt_for_async_gpio_for_port] function must be called inside that function
     /// for the asynchronous functionality to work.
     #[cfg(feature = "vor1x")]
-    pub fn new(pin: Input, irq: va108xx::Interrupt) -> Self {
-        Self { pin, irq }
+    pub fn new(mut pin: Input, irq_config: InterruptConfig) -> Self {
+        // Do not enable GPIO interrupt bit yet.
+        pin.enable_interrupt(irq_config, false);
+        Self { pin }
     }
 
     /// Create a new asynchronous input pin from an [Input] pin. The interrupt ID to be used must be
@@ -246,10 +243,12 @@ impl InputPinAsync {
     /// generic [on_interrupt_for_async_gpio_for_port] function must be called inside that function
     /// for the asynchronous functionality to work.
     #[cfg(feature = "vor4x")]
-    pub fn new(pin: Input) -> Result<Self, PortDoesNotSupportInterrupts> {
+    pub fn new(mut pin: Input) -> Result<Self, PortDoesNotSupportInterrupts> {
         if pin.id().port() == Port::G {
             return Err(PortDoesNotSupportInterrupts);
         }
+        // Do not enable GPIO interrupt bit yet.
+        pin.enable_interrupt(true, false)?;
         Ok(Self { pin })
     }
 
@@ -259,8 +258,7 @@ impl InputPinAsync {
     pub async fn wait_for_high(&mut self) {
         // Unwrap okay, checked pin in constructor.
         #[cfg(feature = "vor1x")]
-        let fut =
-            InputPinFuture::new_with_input_pin(&mut self.pin, self.irq, InterruptEdge::LowToHigh);
+        let fut = InputPinFuture::new_with_input_pin(&mut self.pin, InterruptEdge::LowToHigh);
         #[cfg(feature = "vor4x")]
         let fut =
             InputPinFuture::new_with_input_pin(&mut self.pin, InterruptEdge::LowToHigh).unwrap();
@@ -300,8 +298,7 @@ impl InputPinAsync {
     pub async fn wait_for_low(&mut self) {
         // Unwrap okay, checked pin in constructor.
         #[cfg(feature = "vor1x")]
-        let fut =
-            InputPinFuture::new_with_input_pin(&mut self.pin, self.irq, InterruptEdge::HighToLow);
+        let fut = InputPinFuture::new_with_input_pin(&mut self.pin, InterruptEdge::HighToLow);
         #[cfg(feature = "vor4x")]
         let fut =
             InputPinFuture::new_with_input_pin(&mut self.pin, InterruptEdge::HighToLow).unwrap();
@@ -315,7 +312,7 @@ impl InputPinAsync {
     pub async fn wait_for_falling_edge(&mut self) {
         // Unwrap okay, checked pin in constructor.
         #[cfg(feature = "vor1x")]
-        InputPinFuture::new_with_input_pin(&mut self.pin, self.irq, InterruptEdge::HighToLow).await;
+        InputPinFuture::new_with_input_pin(&mut self.pin, InterruptEdge::HighToLow).await;
         #[cfg(feature = "vor4x")]
         InputPinFuture::new_with_input_pin(&mut self.pin, InterruptEdge::HighToLow)
             .unwrap()
@@ -326,14 +323,14 @@ impl InputPinAsync {
     pub async fn wait_for_rising_edge(&mut self) {
         // Unwrap okay, checked pin in constructor.
         #[cfg(feature = "vor1x")]
-        InputPinFuture::new_with_input_pin(&mut self.pin, self.irq, InterruptEdge::LowToHigh).await;
+        InputPinFuture::new_with_input_pin(&mut self.pin, InterruptEdge::LowToHigh).await;
     }
 
     /// Asynchronously wait until the pin sees any edge (either rising or falling).
     pub async fn wait_for_any_edge(&mut self) {
         // Unwrap okay, checked pin in constructor.
         #[cfg(feature = "vor1x")]
-        InputPinFuture::new_with_input_pin(&mut self.pin, self.irq, InterruptEdge::BothEdges).await;
+        InputPinFuture::new_with_input_pin(&mut self.pin, InterruptEdge::BothEdges).await;
         #[cfg(feature = "vor4x")]
         InputPinFuture::new_with_input_pin(&mut self.pin, InterruptEdge::BothEdges)
             .unwrap()

vorago-shared-hal/src/gpio/ll.rs

@@ -384,32 +384,53 @@ impl LowLevelGpio {
         self.gpio.write_tog_out(self.mask_32());
     }
 
-    #[cfg(feature = "vor1x")]
-    pub fn enable_interrupt(&mut self, irq_cfg: crate::InterruptConfig) {
-        if irq_cfg.route {
-            self.configure_irqsel(irq_cfg.id);
-        }
-        if irq_cfg.enable_in_nvic {
-            unsafe { crate::enable_nvic_interrupt(irq_cfg.id) };
-        }
+    /// Only enabled GPIO peripheral interrupt bit without enabling the interrupt in NVIC
+    /// or routing it in the IRQSEL peripheral for VA108xx devices.
+    #[inline]
+    pub fn enable_interrupt_gpio_only(&mut self) {
         self.gpio.modify_irq_enable(|mut value| {
             value |= 1 << self.id.offset;
             value
         });
     }
 
+    /// Depending on the configuration parameters, does the following:
+    ///
+    /// - Routes the interrupt in the IRQSEL peripheral
+    /// - Enables the interrupt in the NVIC,
+    /// - Enable the GPIO peripheral interrupt bit for this pin if configured.
+    #[cfg(feature = "vor1x")]
+    pub fn enable_interrupt(&mut self, irq_cfg: crate::InterruptConfig, gpio: bool) {
+        if irq_cfg.route {
+            self.configure_irqsel(irq_cfg.id);
+        }
+        if irq_cfg.enable_in_nvic {
+            unsafe { crate::enable_nvic_interrupt(irq_cfg.id) };
+        }
+        if gpio {
+            self.enable_interrupt_gpio_only();
+        }
+    }
+
+    /// Depending on the configuration parameters, does the following:
+    ///
+    /// - Enables the interrupt in the NVIC,
+    /// - Enable the GPIO peripheral interrupt bit for this pin if configured.
     #[cfg(feature = "vor4x")]
     pub fn enable_interrupt(
         &mut self,
         enable_in_nvic: bool,
+        gpio: bool,
     ) -> Result<(), PortDoesNotSupportInterrupts> {
+        if self.id().port() == Port::G {
+            return Err(PortDoesNotSupportInterrupts);
+        }
         if enable_in_nvic {
             unsafe { crate::enable_nvic_interrupt(self.id().irq_unchecked()) };
         }
-        self.gpio.modify_irq_enable(|mut value| {
-            value |= 1 << self.id.offset;
-            value
-        });
+        if gpio {
+            self.enable_interrupt_gpio_only();
+        }
         Ok(())
     }
 

vorago-shared-hal/src/gpio/mod.rs

@@ -132,19 +132,34 @@ impl Input {
         self.0.id()
     }
 
-    #[cfg(feature = "vor1x")]
     #[inline]
-    pub fn enable_interrupt(&mut self, irq_cfg: crate::InterruptConfig) {
-        self.0.enable_interrupt(irq_cfg);
+    pub fn enable_interrupt_gpio_only(&mut self) {
+        self.0.enable_interrupt_gpio_only();
     }
 
+    /// Depending on the configuration parameters, does the following:
+    ///
+    /// - Routes the interrupt in the IRQSEL peripheral
+    /// - Enables the interrupt in the NVIC,
+    /// - Enable the GPIO peripheral interrupt bit for this pin if configured.
+    #[cfg(feature = "vor1x")]
+    #[inline]
+    pub fn enable_interrupt(&mut self, irq_cfg: crate::InterruptConfig, gpio: bool) {
+        self.0.enable_interrupt(irq_cfg, gpio);
+    }
+
+    /// Depending on the configuration parameters, does the following:
+    ///
+    /// - Enables the interrupt in the NVIC,
+    /// - Enable the GPIO peripheral interrupt bit for this pin if configured.
     #[cfg(feature = "vor4x")]
     #[inline]
     pub fn enable_interrupt(
         &mut self,
         enable_in_nvic: bool,
+        gpio: bool,
     ) -> Result<(), ll::PortDoesNotSupportInterrupts> {
-        self.0.enable_interrupt(enable_in_nvic)
+        self.0.enable_interrupt(enable_in_nvic, gpio)
     }
 
     #[inline]

vorago-shared-hal/src/gpio/regs.rs

@@ -58,7 +58,8 @@ pub struct Gpio {
     /// Read-only register which shows enabled and active interrupts. Called IRQ_end by Vorago.
     #[mmio(PureRead)]
     irq_status: u32,
-    #[mmio(PureRead)]
+    // Reading this register clears it.
+    #[mmio(Read)]
     edge_status: u32,
 
     #[cfg(feature = "vor1x")]

vorago-shared-hal/src/lib.rs

@@ -137,7 +137,7 @@ impl Port {
     /// # Safety
     ///
     /// Circumvents ownership and safety guarantees by the HAL.
-    pub unsafe fn steal_gpio(&self) -> gpio::regs::MmioGpio<'static> {
+    pub unsafe fn steal_regs(&self) -> gpio::regs::MmioGpio<'static> {
         gpio::regs::Gpio::new_mmio(*self)
     }
 }

vorago-shared-hal/src/spi/asynch.rs

@@ -1,4 +1,4 @@
-use core::{cell::RefCell, convert::Infallible};
+use core::cell::RefCell;
 
 use arbitrary_int::u5;
 use critical_section::Mutex;
@@ -8,7 +8,7 @@ use raw_slice::{RawBufSlice, RawBufSliceMut};
 
 use crate::{
     shared::{FifoClear, TriggerLevel},
-    spi::regs::{Data, InterruptClear, InterruptControl, InterruptStatus},
+    spi::regs::{Data, InterruptClear, InterruptControl},
 };
 
 #[cfg(feature = "vor1x")]
@@ -23,6 +23,17 @@ static TRANSFER_CONTEXTS: [Mutex<RefCell<TransferContext>>; NUM_SPIS] =
 // critical section.
 static DONE: [AtomicBool; NUM_SPIS] = [const { AtomicBool::new(false) }; NUM_SPIS];
 
+#[derive(Debug, Clone, Copy, thiserror::Error)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+#[error("SPI RX FIFO overrun")]
+pub struct RxOverrunError;
+
+impl embedded_hal_async::spi::Error for RxOverrunError {
+    fn kind(&self) -> embedded_hal::spi::ErrorKind {
+        embedded_hal::spi::ErrorKind::Overrun
+    }
+}
+
 /// This is a generic interrupt handler to handle asynchronous SPI  operations for a given
 /// SPI peripheral.
 ///
@@ -30,18 +41,23 @@ static DONE: [AtomicBool; NUM_SPIS] = [const { AtomicBool::new(false) }; NUM_SPI
 /// the given SPI bank.
 pub fn on_interrupt(peripheral: super::Bank) {
     let mut spi = unsafe { peripheral.steal_regs() };
-    let idx = peripheral as usize;
-    let interrupt_enabled = spi.read_interrupt_control();
-    let isr = spi.read_interrupt_status();
-    // IRQ is not related.
-    if interrupt_enabled.raw_value() == 0 {
-        return;
-    }
+    let index = peripheral as usize;
+    let enabled_irqs = spi.read_interrupt_control();
+    spi.write_interrupt_clear(InterruptClear::ALL);
     // Prevent spurious interrupts from messing with out logic here.
     spi.write_interrupt_control(InterruptControl::DISABLE_ALL);
-    spi.write_interrupt_clear(InterruptClear::ALL);
+    // IRQ is not related.
+    if enabled_irqs.raw_value() == 0 {
+        reset_trigger_levels(&mut spi);
+        spi.write_fifo_clear(FifoClear::ALL);
+        return;
+    }
+    if spi.read_interrupt_status().rx_overrun() {
+        // Not sure how to otherwise handle this cleanly..
+        return handle_rx_overrun(&mut spi, index);
+    }
     let mut context = critical_section::with(|cs| {
-        let context_ref = TRANSFER_CONTEXTS[idx].borrow(cs);
+        let context_ref = TRANSFER_CONTEXTS[index].borrow(cs);
         *context_ref.borrow()
     });
     // No transfer active.
@@ -50,30 +66,47 @@ pub fn on_interrupt(peripheral: super::Bank) {
     }
     let transfer_type = context.transfer_type.unwrap();
     match transfer_type {
-        TransferType::Read => on_interrupt_read(idx, &mut context, &mut spi, isr),
-        TransferType::Write => on_interrupt_write(idx, &mut context, &mut spi, isr),
-        TransferType::Transfer => on_interrupt_transfer(idx, &mut context, &mut spi, isr),
+        TransferType::Read => on_interrupt_read(index, &mut context, &mut spi, enabled_irqs),
+        TransferType::Write => on_interrupt_write(index, &mut context, &mut spi, enabled_irqs),
+        TransferType::Transfer => {
+            on_interrupt_transfer(index, &mut context, &mut spi, enabled_irqs)
+        }
         TransferType::TransferInPlace => {
-            on_interrupt_transfer_in_place(idx, &mut context, &mut spi, isr)
+            on_interrupt_transfer_in_place(index, &mut context, &mut spi, enabled_irqs)
         }
     };
 }
 
+fn handle_rx_overrun(spi: &mut super::regs::MmioSpi<'static>, idx: usize) {
+    critical_section::with(|cs| {
+        let context_ref = TRANSFER_CONTEXTS[idx].borrow(cs);
+        context_ref.borrow_mut().rx_overrun = true;
+    });
+    // Clean up, restore clean state.
+    reset_trigger_levels(spi);
+    spi.write_fifo_clear(FifoClear::ALL);
+    // Interrupts were already disabled and cleared.
+    DONE[idx].store(true, core::sync::atomic::Ordering::Relaxed);
+    WAKERS[idx].wake();
+}
+
 fn on_interrupt_read(
     idx: usize,
     context: &mut TransferContext,
     spi: &mut super::regs::MmioSpi<'static>,
-    isr: InterruptStatus,
+    enabled_irqs: InterruptControl,
 ) {
     let read_slice = unsafe { context.rx_slice.get_mut().unwrap() };
     let transfer_len = read_slice.len();
 
     // Read data from RX FIFO first.
-    let read_len = calculate_read_len(spi, isr, transfer_len, context.rx_progress);
-    (0..read_len).for_each(|_| {
-        read_slice[context.rx_progress] = (spi.read_data().data() & 0xFF) as u8;
-        context.rx_progress += 1;
-    });
+    while spi.read_status().rx_not_empty() {
+        let data = spi.read_data();
+        if context.rx_progress < transfer_len {
+            read_slice[context.rx_progress] = (data.data() & 0xFF) as u8;
+            context.rx_progress += 1;
+        }
+    }
 
     // The FIFO still needs to be pumped.
     while context.tx_progress < read_slice.len() && spi.read_status().tx_not_full() {
@@ -81,24 +114,25 @@ fn on_interrupt_read(
         context.tx_progress += 1;
     }
 
-    isr_finish_handler(idx, spi, context, transfer_len)
+    isr_finish_handler(idx, spi, context, transfer_len, enabled_irqs)
 }
 
 fn on_interrupt_write(
     idx: usize,
     context: &mut TransferContext,
     spi: &mut super::regs::MmioSpi<'static>,
-    isr: InterruptStatus,
+    enabled_irqs: InterruptControl,
 ) {
     let write_slice = unsafe { context.tx_slice.get().unwrap() };
     let transfer_len = write_slice.len();
 
     // Read data from RX FIFO first.
-    let read_len = calculate_read_len(spi, isr, transfer_len, context.rx_progress);
-    (0..read_len).for_each(|_| {
+    while spi.read_status().rx_not_empty() {
         spi.read_data();
-        context.rx_progress += 1;
-    });
+        if context.rx_progress < transfer_len {
+            context.rx_progress += 1;
+        }
+    }
 
     // Data still needs to be sent
     while context.tx_progress < transfer_len && spi.read_status().tx_not_full() {
@@ -108,14 +142,14 @@ fn on_interrupt_write(
         context.tx_progress += 1;
     }
 
-    isr_finish_handler(idx, spi, context, transfer_len)
+    isr_finish_handler(idx, spi, context, transfer_len, enabled_irqs)
 }
 
 fn on_interrupt_transfer(
     idx: usize,
     context: &mut TransferContext,
     spi: &mut super::regs::MmioSpi<'static>,
-    isr: InterruptStatus,
+    enabled_irqs: InterruptControl,
 ) {
     let read_slice = unsafe { context.rx_slice.get_mut().unwrap() };
     let read_len = read_slice.len();
@@ -133,28 +167,28 @@ fn on_interrupt_transfer(
             // Dummy write.
             spi.write_data(Data::new_with_raw_value(0));
         }
+        // Always increment this.
         context.tx_progress += 1;
     }
 
     // Read data from RX FIFO.
-    let read_len = calculate_read_len(spi, isr, transfer_len, context.rx_progress);
-    (0..read_len).for_each(|_| {
+    while spi.read_status().rx_not_empty() {
+        let data = spi.read_data();
         if context.rx_progress < read_len {
-            read_slice[context.rx_progress] = (spi.read_data().data() & 0xFF) as u8;
-        } else {
-            spi.read_data();
+            read_slice[context.rx_progress] = (data.data() & 0xFF) as u8;
         }
+        // Always increment this.
         context.rx_progress += 1;
-    });
+    }
 
-    isr_finish_handler(idx, spi, context, transfer_len)
+    isr_finish_handler(idx, spi, context, transfer_len, enabled_irqs)
 }
 
 fn on_interrupt_transfer_in_place(
     idx: usize,
     context: &mut TransferContext,
     spi: &mut super::regs::MmioSpi<'static>,
-    isr: InterruptStatus,
+    enabled_irqs: InterruptControl,
 ) {
     let transfer_slice = unsafe { context.rx_slice.get_mut().unwrap() };
     let transfer_len = transfer_slice.len();
@@ -166,29 +200,15 @@ fn on_interrupt_transfer_in_place(
         context.tx_progress += 1;
     }
     // Read data from RX FIFO.
-    let read_len = calculate_read_len(spi, isr, transfer_len, context.rx_progress);
-    (0..read_len).for_each(|_| {
-        transfer_slice[context.rx_progress] = (spi.read_data().data() & 0xFF) as u8;
-        context.rx_progress += 1;
-    });
-
-    isr_finish_handler(idx, spi, context, transfer_len)
-}
-
-fn calculate_read_len(
-    spi: &mut super::regs::MmioSpi<'static>,
-    isr: InterruptStatus,
-    total_read_len: usize,
-    rx_progress: usize,
-) -> usize {
-    if isr.rx() {
-        core::cmp::min(super::FIFO_DEPTH, total_read_len - rx_progress)
-    } else if spi.read_status().rx_not_empty() {
-        let fifo_level = spi.read_state().rx_fifo();
-        core::cmp::min(total_read_len - rx_progress, fifo_level as usize)
-    } else {
-        0
+    while spi.read_status().rx_not_empty() {
+        let data = spi.read_data();
+        if context.rx_progress < transfer_len {
+            transfer_slice[context.rx_progress] = (data.data() & 0xFF) as u8;
+            context.rx_progress += 1;
+        }
     }
+
+    isr_finish_handler(idx, spi, context, transfer_len, enabled_irqs)
 }
 
 /// Generic handler after RX FIFO and TX FIFO were handled. Checks and handles finished
@@ -198,49 +218,71 @@ fn isr_finish_handler(
     spi: &mut super::regs::MmioSpi<'static>,
     context: &mut TransferContext,
     transfer_len: usize,
+    enabled: InterruptControl,
 ) {
     // Transfer finish condition.
     if context.rx_progress == context.tx_progress && context.rx_progress == transfer_len {
-        finish_transfer(idx, context, spi);
+        finish_transfer(spi, idx, context);
         return;
     }
-
-    unfinished_transfer(spi, transfer_len, context.rx_progress);
-
     // If the transfer is done, the context structure was already written back.
     // Write back updated context structure.
     critical_section::with(|cs| {
         let context_ref = TRANSFER_CONTEXTS[idx].borrow(cs);
         *context_ref.borrow_mut() = *context;
     });
+    unfinished_transfer(spi, transfer_len, context, enabled);
 }
 
 fn finish_transfer(
+    spi: &mut super::regs::MmioSpi<'static>,
     idx: usize,
     context: &mut TransferContext,
-    spi: &mut super::regs::MmioSpi<'static>,
 ) {
     // Write back updated context structure.
     critical_section::with(|cs| {
         let context_ref = TRANSFER_CONTEXTS[idx].borrow(cs);
         *context_ref.borrow_mut() = *context;
     });
-    spi.write_rx_fifo_trigger(TriggerLevel::new(u5::new(0x08)));
-    spi.write_tx_fifo_trigger(TriggerLevel::new(u5::new(0x00)));
+    // Clean up, restore clean state.
+    reset_trigger_levels(spi);
+    spi.write_fifo_clear(FifoClear::ALL);
     // Interrupts were already disabled and cleared.
     DONE[idx].store(true, core::sync::atomic::Ordering::Relaxed);
     WAKERS[idx].wake();
 }
 
+#[inline]
 fn unfinished_transfer(
     spi: &mut super::regs::MmioSpi<'static>,
     transfer_len: usize,
-    rx_progress: usize,
+    context: &TransferContext,
+    enabled_irqs: InterruptControl,
 ) {
-    let new_trig_level = core::cmp::min(super::FIFO_DEPTH, transfer_len - rx_progress);
+    let new_trig_level = core::cmp::min(super::FIFO_DEPTH, transfer_len - context.rx_progress);
     spi.write_rx_fifo_trigger(TriggerLevel::new(u5::new(new_trig_level as u8)));
+
+    // If TX was already enabled and the transfer is finished, stop enabling it. Otherwise, we can
+    // become stuck in an interrupt loop. In any other case, enable it. I am not fully sure
+    // why this is necessary and why we can not stop interrupts as soon as we have the full
+    // TX progress, but tests with ADCs have shown that not doing this causes timeouts.
+    let enable_tx = !(enabled_irqs.tx() && context.tx_progress == transfer_len);
+
     // Re-enable interrupts with the new RX FIFO trigger level.
-    spi.write_interrupt_control(InterruptControl::ENABLE_ALL);
+    spi.write_interrupt_control(
+        InterruptControl::builder()
+            .with_tx(enable_tx)
+            .with_rx(true)
+            .with_rx_timeout(true)
+            .with_rx_overrun(true)
+            .build(),
+    );
+}
+
+#[inline]
+fn reset_trigger_levels(spi: &mut super::regs::MmioSpi<'static>) {
+    spi.write_rx_fifo_trigger(TriggerLevel::new(u5::new(0x08)));
+    spi.write_tx_fifo_trigger(TriggerLevel::new(u5::new(0x00)));
 }
 
 #[derive(Debug, Clone, Copy)]
@@ -259,6 +301,7 @@ pub struct TransferContext {
     rx_progress: usize,
     tx_slice: RawBufSlice,
     rx_slice: RawBufSliceMut,
+    rx_overrun: bool,
 }
 
 #[allow(clippy::new_without_default)]
@@ -270,6 +313,7 @@ impl TransferContext {
             rx_progress: 0,
             tx_slice: RawBufSlice::new_nulled(),
             rx_slice: RawBufSliceMut::new_nulled(),
+            rx_overrun: false,
         }
     }
 }
@@ -452,7 +496,7 @@ impl<'spi> SpiFuture<'spi> {
 }
 
 impl<'spi> Future for SpiFuture<'spi> {
-    type Output = ();
+    type Output = Result<(), RxOverrunError>;
 
     fn poll(
         self: core::pin::Pin<&mut Self>,
@@ -460,14 +504,19 @@ impl<'spi> Future for SpiFuture<'spi> {
     ) -> core::task::Poll<Self::Output> {
         WAKERS[self.bank as usize].register(cx.waker());
         if DONE[self.bank as usize].swap(false, core::sync::atomic::Ordering::Relaxed) {
-            critical_section::with(|cs| {
+            let rx_overrun = critical_section::with(|cs| {
                 let mut ctx = TRANSFER_CONTEXTS[self.bank as usize]
                     .borrow(cs)
                     .borrow_mut();
+                let overrun = ctx.rx_overrun;
                 *ctx = TransferContext::default();
+                overrun
             });
             self.finished_regularly.set(true);
-            return core::task::Poll::Ready(());
+            if rx_overrun {
+                return core::task::Poll::Ready(Err(RxOverrunError));
+            }
+            return core::task::Poll::Ready(Ok(()));
         }
         core::task::Poll::Pending
     }
@@ -554,28 +603,36 @@ impl SpiAsync {
 }
 
 impl embedded_hal_async::spi::ErrorType for SpiAsync {
-    type Error = Infallible;
+    type Error = RxOverrunError;
 }
 
 impl embedded_hal_async::spi::SpiBus for SpiAsync {
     async fn read(&mut self, words: &mut [u8]) -> Result<(), Self::Error> {
-        self.read(words).unwrap().await;
-        Ok(())
+        if words.is_empty() {
+            return Ok(());
+        }
+        self.read(words).unwrap().await
     }
 
     async fn write(&mut self, words: &[u8]) -> Result<(), Self::Error> {
-        self.write(words).unwrap().await;
-        Ok(())
+        if words.is_empty() {
+            return Ok(());
+        }
+        self.write(words).unwrap().await
     }
 
     async fn transfer(&mut self, read: &mut [u8], write: &[u8]) -> Result<(), Self::Error> {
-        self.transfer(read, write).unwrap().await;
-        Ok(())
+        if read.is_empty() && write.is_empty() {
+            return Ok(());
+        }
+        self.transfer(read, write).unwrap().await
     }
 
     async fn transfer_in_place(&mut self, words: &mut [u8]) -> Result<(), Self::Error> {
-        self.transfer_in_place(words).unwrap().await;
-        Ok(())
+        if words.is_empty() {
+            return Ok(());
+        }
+        self.transfer_in_place(words).unwrap().await
     }
 
     async fn flush(&mut self) -> Result<(), Self::Error> {