diff --git a/embassy-rp/src/spi.rs b/embassy-rp/src/spi.rs index 2cd2aa753..7da214743 100644 --- a/embassy-rp/src/spi.rs +++ b/embassy-rp/src/spi.rs @@ -90,10 +90,16 @@ impl<'d, T: Instance, M: Mode> Spi<'d, T, M> { w.set_sph(config.phase == Phase::CaptureOnSecondTransition); w.set_scr(postdiv); }); - p.cr1().write(|w| { - w.set_sse(true); // enable + + // Always enable DREQ signals -- harmless if DMA is not listening + p.dmacr().write(|reg| { + reg.set_rxdmae(true); + reg.set_txdmae(true); }); + // finally, enable. + p.cr1().write(|w| w.set_sse(true)); + if let Some(pin) = &clk { pin.io().ctrl().write(|w| w.set_funcsel(1)); } @@ -329,9 +335,6 @@ impl<'d, T: Instance> Spi<'d, T, Async> { pub async fn write(&mut self, buffer: &[u8]) -> Result<(), Error> { let tx_ch = self.tx_dma.as_mut().unwrap(); let tx_transfer = unsafe { - self.inner.regs().dmacr().modify(|reg| { - reg.set_txdmae(true); - }); // If we don't assign future to a variable, the data register pointer // is held across an await and makes the future non-Send. crate::dma::write(tx_ch, buffer, self.inner.regs().dr().ptr() as *mut _, T::TX_DREQ) @@ -354,13 +357,6 @@ impl<'d, T: Instance> Spi<'d, T, Async> { } pub async fn read(&mut self, buffer: &mut [u8]) -> Result<(), Error> { - unsafe { - self.inner.regs().dmacr().write(|reg| { - reg.set_rxdmae(true); - reg.set_txdmae(true); - }) - }; - // Start RX first. Transfer starts when TX starts, if RX // is not started yet we might lose bytes. let rx_ch = self.rx_dma.as_mut().unwrap(); @@ -392,13 +388,6 @@ impl<'d, T: Instance> Spi<'d, T, Async> { let (_, tx_len) = crate::dma::slice_ptr_parts(tx_ptr); let (_, rx_len) = crate::dma::slice_ptr_parts_mut(rx_ptr); - unsafe { - self.inner.regs().dmacr().write(|reg| { - reg.set_rxdmae(true); - reg.set_txdmae(true); - }) - }; - // Start RX first. Transfer starts when TX starts, if RX // is not started yet we might lose bytes. let rx_ch = self.rx_dma.as_mut().unwrap();