maybe fix program not exiting

.gitea/workflows/build-kernel.yml

@@ -142,6 +142,7 @@ jobs:
           cp -r dist/modules "$root"/       # modules/iec_listener_<kernel_version>.ko
           cp kernel/selftest.sh "$root"/    # one-shot hardware self-test
           cp launch.sh "$root"/             # load module -> run frontend -> unload
+          chmod +x "$root/launch.sh" "$root/selftest.sh"
           # iecpoc Python frontend + its packaging metadata. launch.sh pip-installs
           # this on the Pi; the build reads pyproject.toml's readme = "README.md",
           # so README.md must travel with it. __pycache__ is stripped to stay clean.

kernel/iec_listener.c

@@ -286,6 +286,10 @@ static void run_state_machine(void)
 		bool eoi;
 		enum iec_rx rc;
 
+		if (kthread_should_stop()) {
+			iec_data_release();
+			return;
+		}
 		if (db_reset_asserted())
 			goto reset;
 
@@ -313,6 +317,10 @@ static void run_state_machine(void)
 		/* LISTENER: data phase */
 		emit_record(IEC_KIND_EVENT, IEC_EV_ATN_RELEASED, IEC_FLAG_ADDRESSED);
 		for (;;) {
+			if (kthread_should_stop()) {
+				iec_data_release();
+				return;
+			}
 			if (db_reset_asserted())
 				goto reset;
 			if (db_atn_asserted()) {

kernel/iec_timing.h

@@ -30,7 +30,7 @@
  * confirmed-working reference listener (5 us). sd2iec / the 1571 ROM
  * use a comparable few-microsecond debounce. Far shorter than a real IEC bit
  * (tens of us), so it never smears valid data. */
-#define IEC_DEBOUNCE_US      10
+#define IEC_DEBOUNCE_US      5
 
 /* Between-bytes minimum hold before the talker releases CLK for the next byte
  * (Tbb). We simply wait for the next CLK transition; this is documentary. */