don't use embassy_time for blocking_delay_us on stm32wlex low-power

1 files changed, 12 insertions, 8 deletions

diff --git a/embassy-stm32/src/adc/mod.rs b/embassy-stm32/src/adc/mod.rs
index 22ed8295f..ea7341f75 100644
--- a/embassy-stm32/src/adc/mod.rs
+++ b/embassy-stm32/src/adc/mod.rs
@@ -87,14 +87,18 @@ pub(crate) trait SealedAdcChannel<T> {
 /// Performs a busy-wait delay for a specified number of microseconds.
 #[allow(unused)]
 pub(crate) fn blocking_delay_us(us: u32) {
-    #[cfg(feature = "time")]
-    embassy_time::block_for(embassy_time::Duration::from_micros(us as u64));
-    #[cfg(not(feature = "time"))]
-    {
-        let freq = unsafe { crate::rcc::get_freqs() }.sys.to_hertz().unwrap().0 as u64;
-        let us = us as u64;
-        let cycles = freq * us / 1_000_000;
-        cortex_m::asm::delay(cycles as u32);
+    cfg_if::cfg_if! {
+        // this does strange things on stm32wlx in low power mode depending on exactly when it's called
+        // as in sometimes 15 us (1 tick) would take > 20 seconds.
+        if #[cfg(all(feature = "time", all(not(feature = "low-power"), not(stm32wlex))))] {
+            let duration = embassy_time::Duration::from_micros(us as u64);
+            embassy_time::block_for(duration);
+        } else {
+            let freq = unsafe { crate::rcc::get_freqs() }.sys.to_hertz().unwrap().0 as u64;
+            let us = us as u64;
+            let cycles = freq * us / 1_000_000;
+            cortex_m::asm::delay(cycles as u32);
+        }
     }
 }