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rp: let SPI RX overflow during async write

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This commit is contained in:
Alex Martens 2022-09-18 12:23:17 -07:00
parent ab1a6889a6
commit 295cc997ae
2 changed files with 17 additions and 37 deletions
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19
embassy-rp/src/dma.rs
View File

@ -56,25 +56,6 @@ pub unsafe fn read<'a, C: Channel, W: Word>(
)
}
pub unsafe fn read_repeated<'a, C: Channel, W: Word>(
ch: impl Peripheral<P = C> + 'a,
from: *const W,
len: usize,
dreq: u8,
) -> Transfer<'a, C> {
let mut dummy: u32 = 0;
copy_inner(
ch,
from as *const u32,
&mut dummy as *mut u32,
len,
W::size(),
false,
false,
dreq,
)
}
pub unsafe fn write<'a, C: Channel, W: Word>(
ch: impl Peripheral<P = C> + 'a,
from: *const [W],

35
embassy-rp/src/spi.rs
View File

@ -325,30 +325,29 @@ impl<'d, T: Instance> Spi<'d, T, Async> {
}
pub async fn write(&mut self, buffer: &[u8]) -> Result<(), Error> {
unsafe {
self.inner.regs().dmacr().write(|reg| {
reg.set_rxdmae(true);
reg.set_txdmae(true);
})
};
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)
};
let rx_ch = self.rx_dma.as_mut().unwrap();
let rx_transfer = unsafe {
// 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::read_repeated(
rx_ch,
self.inner.regs().dr().ptr() as *const u8,
buffer.len(),
T::RX_DREQ,
)
};
join(tx_transfer, rx_transfer).await;
tx_transfer.await;
let p = self.inner.regs();
unsafe {
while p.sr().read().bsy() {}
// clear RX FIFO contents to prevent stale reads
while p.sr().read().rne() {
let _: u16 = p.dr().read().data();
}
// clear RX overrun interrupt
p.icr().write(|w| w.set_roric(true));
}
Ok(())
}