[UCPD] Don't disable ucpd rx after each reception

When disabling the UCPD RX after every reception it's relatively easy to
drop packets. This seems to happen in particular with GoodCRC packets
which can be sent very quickly by a receiver. To avoid this enable
reception as soon as the pd phy get split out (preparing for packet
processing) and only disable again when the pd phy gets dropped.

1 files changed, 4 insertions, 2 deletions

diff --git a/embassy-stm32/src/ucpd.rs b/embassy-stm32/src/ucpd.rs
index 89e2f5d49..cbec85ff3 100644
--- a/embassy-stm32/src/ucpd.rs
+++ b/embassy-stm32/src/ucpd.rs
@@ -169,6 +169,9 @@ impl<'d, T: Instance> Ucpd<'d, T> {
         // Enable hard reset receive interrupt.
         r.imr().modify(|w| w.set_rxhrstdetie(true));
 
+        // Enable PD packet reception
+        r.cr().modify(|w| w.set_phyrxen(true));
+
         // Both parts must be dropped before the peripheral can be disabled.
         T::state().drop_not_ready.store(true, Ordering::Relaxed);
 
@@ -319,6 +322,7 @@ pub struct PdPhy<'d, T: Instance> {
 
 impl<'d, T: Instance> Drop for PdPhy<'d, T> {
     fn drop(&mut self) {
+        T::REGS.cr().modify(|w| w.set_phyrxen(false));
         // Check if the Type-C part was dropped already.
         let drop_not_ready = &T::state().drop_not_ready;
         if drop_not_ready.load(Ordering::Relaxed) {
@@ -350,9 +354,7 @@ impl<'d, T: Instance> PdPhy<'d, T> {
             w.set_rxmsgendcf(true);
         });
 
-        r.cr().modify(|w| w.set_phyrxen(true));
         let _on_drop = OnDrop::new(|| {
-            r.cr().modify(|w| w.set_phyrxen(false));
             Self::enable_rx_interrupt(false);
         });