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stm32/usb: use separate irq flags.

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- Fixes race condition that could cause losing irqs (because `if flags != 0` was clearing all)
- Doesn't need CAS, which is nice for thumbv6.
This commit is contained in:
Dario Nieuwenhuis
2022-12-23 20:45:51 +01:00
parent 40ef66cdfb
commit cd9a65ba39
1 changed files with 33 additions and 33 deletions
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66
embassy-stm32/src/usb/usb.rs
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@@ -2,10 +2,9 @@
use core::future::poll_fn;
use core::marker::PhantomData;
use core::sync::atomic::Ordering;
use core::sync::atomic::{AtomicBool, Ordering};
use core::task::Poll;
use atomic_polyfill::{AtomicBool, AtomicU8};
use embassy_hal_common::into_ref;
use embassy_sync::waitqueue::AtomicWaker;
use embassy_time::{block_for, Duration};
@@ -35,10 +34,9 @@ static BUS_WAKER: AtomicWaker = NEW_AW;
static EP0_SETUP: AtomicBool = AtomicBool::new(false);
static EP_IN_WAKERS: [AtomicWaker; EP_COUNT] = [NEW_AW; EP_COUNT];
static EP_OUT_WAKERS: [AtomicWaker; EP_COUNT] = [NEW_AW; EP_COUNT];
static IRQ_FLAGS: AtomicU8 = AtomicU8::new(0);
const IRQ_FLAG_RESET: u8 = 0x01;
const IRQ_FLAG_SUSPEND: u8 = 0x02;
const IRQ_FLAG_RESUME: u8 = 0x04;
static IRQ_RESET: AtomicBool = AtomicBool::new(false);
static IRQ_SUSPEND: AtomicBool = AtomicBool::new(false);
static IRQ_RESUME: AtomicBool = AtomicBool::new(false);
fn convert_type(t: EndpointType) -> EpType {
match t {
@@ -184,47 +182,51 @@ impl<'d, T: Instance> Driver<'d, T> {
let istr = regs.istr().read();
let mut flags: u8 = 0;
if istr.susp() {
//trace!("USB IRQ: susp");
flags |= IRQ_FLAG_SUSPEND;
IRQ_SUSPEND.store(true, Ordering::Relaxed);
regs.cntr().modify(|w| {
w.set_fsusp(true);
w.set_lpmode(true);
})
});
// Write 0 to clear.
let mut clear = regs::Istr(!0);
clear.set_susp(false);
regs.istr().write_value(clear);
// Wake main thread.
BUS_WAKER.wake();
}
if istr.wkup() {
//trace!("USB IRQ: wkup");
flags |= IRQ_FLAG_RESUME;
IRQ_RESUME.store(true, Ordering::Relaxed);
regs.cntr().modify(|w| {
w.set_fsusp(false);
w.set_lpmode(false);
})
});
// Write 0 to clear.
let mut clear = regs::Istr(!0);
clear.set_wkup(false);
regs.istr().write_value(clear);
// Wake main thread.
BUS_WAKER.wake();
}
if istr.reset() {
//trace!("USB IRQ: reset");
flags |= IRQ_FLAG_RESET;
IRQ_RESET.store(true, Ordering::Relaxed);
// Write 0 to clear.
let mut clear = regs::Istr(!0);
clear.set_reset(false);
regs.istr().write_value(clear);
}
if flags != 0 {
// Send irqs to main thread.
IRQ_FLAGS.fetch_or(flags, Ordering::AcqRel);
// Wake main thread.
BUS_WAKER.wake();
// Clear them
let mut mask = regs::Istr(0);
mask.set_wkup(true);
mask.set_susp(true);
mask.set_reset(true);
regs.istr().write_value(regs::Istr(!(istr.0 & mask.0)));
}
if istr.ctr() {
@@ -436,17 +438,15 @@ impl<'d, T: Instance> driver::Bus for Bus<'d, T> {
if self.inited {
let regs = T::regs();
let flags = IRQ_FLAGS.load(Ordering::Acquire);
if flags & IRQ_FLAG_RESUME != 0 {
IRQ_FLAGS.fetch_and(!IRQ_FLAG_RESUME, Ordering::AcqRel);
if IRQ_RESUME.load(Ordering::Acquire) {
IRQ_RESUME.store(false, Ordering::Relaxed);
return Poll::Ready(Event::Resume);
}
if flags & IRQ_FLAG_RESET != 0 {
IRQ_FLAGS.fetch_and(!IRQ_FLAG_RESET, Ordering::AcqRel);
if IRQ_RESET.load(Ordering::Acquire) {
IRQ_RESET.store(false, Ordering::Relaxed);
trace!("RESET REGS WRITINGINGING");
trace!("RESET");
regs.daddr().write(|w| {
w.set_ef(true);
w.set_add(0);
@@ -475,8 +475,8 @@ impl<'d, T: Instance> driver::Bus for Bus<'d, T> {
return Poll::Ready(Event::Reset);
}
if flags & IRQ_FLAG_SUSPEND != 0 {
IRQ_FLAGS.fetch_and(!IRQ_FLAG_SUSPEND, Ordering::AcqRel);
if IRQ_SUSPEND.load(Ordering::Acquire) {
IRQ_SUSPEND.store(false, Ordering::Relaxed);
return Poll::Ready(Event::Suspend);
}