From 6454b55b4a4f450aa3dd9a9b323f5766608b0a4d Mon Sep 17 00:00:00 2001
From: Kaspar Schleiser <kaspar@schleiser.de>
Date: Tue, 22 Oct 2024 15:22:51 +0200
Subject: [PATCH] fix(threads): xtensa: fix enabling scheduler interrupt

---
 src/riot-rs-embassy/Cargo.toml |  2 +-
 src/riot-rs-esp/Cargo.toml     |  3 +++
 src/riot-rs-esp/src/lib.rs     | 14 ++++++++++++++
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/riot-rs-embassy/Cargo.toml b/src/riot-rs-embassy/Cargo.toml
index b515bf02d..fb7549971 100644
--- a/src/riot-rs-embassy/Cargo.toml
+++ b/src/riot-rs-embassy/Cargo.toml
@@ -94,7 +94,7 @@ wifi = []
 wifi-cyw43 = ["riot-rs-rp/wifi-cyw43", "net", "wifi"]
 wifi-esp = ["riot-rs-esp/wifi-esp", "net", "wifi"]
 
-threading = ["dep:riot-rs-threads"]
+threading = ["dep:riot-rs-threads", "riot-rs-esp/threading"]
 override-network-config = []
 override-usb-config = []
 
diff --git a/src/riot-rs-esp/Cargo.toml b/src/riot-rs-esp/Cargo.toml
index 9bc87fd51..3e6c31e78 100644
--- a/src/riot-rs-esp/Cargo.toml
+++ b/src/riot-rs-esp/Cargo.toml
@@ -77,6 +77,9 @@ i2c = [
 ## Enables defmt support.
 defmt = ["dep:defmt", "esp-wifi?/defmt", "fugit?/defmt"]
 
+## Enables threading support.
+threading = []
+
 ## Enables Wi-Fi support.
 wifi = []
 
diff --git a/src/riot-rs-esp/src/lib.rs b/src/riot-rs-esp/src/lib.rs
index 4feeae9b2..b0e444c30 100644
--- a/src/riot-rs-esp/src/lib.rs
+++ b/src/riot-rs-esp/src/lib.rs
@@ -65,6 +65,20 @@ pub use esp_hal_embassy::Executor;
 pub fn init() -> OptionalPeripherals {
     let mut peripherals = OptionalPeripherals::from(esp_hal::init(esp_hal::Config::default()));
 
+    #[cfg(feature = "threading")]
+    {
+        use esp_hal::{interrupt, peripherals::Interrupt};
+        // Since https://github.com/esp-rs/esp-hal/pull/2091,
+        // `esp_hal::init()` resets all interrupts.
+        // That also disables our scheduler interrupt, which was previously enabled
+        // in `riot_rs_threads::arch::xtensa`.
+        // So, re-enable it here.
+
+        // Panics if `FROM_CPU_INTR1` is among `esp_hal::interrupt::RESERVED_INTERRUPTS`,
+        // which isn't the case.
+        interrupt::enable(Interrupt::FROM_CPU_INTR1, interrupt::Priority::min()).unwrap();
+    }
+
     #[cfg(feature = "wifi-esp")]
     {
         use esp_hal::timer::timg::TimerGroup;