Fixes for pulsein tick handling

Author: siehputz

ports/atmel-samd/common-hal/pulseio/PulseIn.c

@@ -44,6 +44,7 @@
 #include "shared-bindings/pulseio/PulseIn.h"
 #include "supervisor/shared/tick.h"
 #include "supervisor/shared/translate.h"
+#include "supervisor/port.h"
 
 // This timer is shared amongst all PulseIn objects as a higher resolution clock.
 static uint8_t refcount = 0;
@@ -77,7 +78,7 @@ static void pulsein_set_config(pulseio_pulsein_obj_t* self, bool first_edge) {
 }
 
 void pulsein_interrupt_handler(uint8_t channel) {
-    // turn off interrupts while in the handler
+    // Turn off interrupts while in handler
     common_hal_mcu_disable_interrupts();
     // Grab the current time first.
     uint32_t current_overflow = overflow_count;
@@ -90,10 +91,8 @@ void pulsein_interrupt_handler(uint8_t channel) {
     uint32_t current_count = tc->COUNT16.COUNT.reg;
 
     pulseio_pulsein_obj_t* self = get_eic_channel_data(channel);
-    if (!supervisor_background_tasks_ok() ) {
-        common_hal_mcu_enable_interrupts();
-        mp_raise_RuntimeError(translate("Input taking too long"));
-        return;
+    if (self->len == 0) {
+        update_background_ticks();
     }
     if (self->first_edge) {
         self->first_edge = false;
@@ -123,6 +122,11 @@ void pulsein_interrupt_handler(uint8_t channel) {
             self->start++;
         }
     }
+    if (!supervisor_background_tasks_ok() ) {
+        common_hal_mcu_enable_interrupts();
+        mp_raise_RuntimeError(translate("Input taking too long"));
+        return;
+    }
     self->last_overflow = current_overflow;
     self->last_count = current_count;
     common_hal_mcu_enable_interrupts();
@@ -304,7 +308,6 @@ uint16_t common_hal_pulseio_pulsein_popleft(pulseio_pulsein_obj_t* self) {
     self->start = (self->start + 1) % self->maxlen;
     self->len--;
     common_hal_mcu_enable_interrupts();
-
     return value;
 }
 

ports/atmel-samd/common-hal/pulseio/PulseIn.h

@@ -50,6 +50,7 @@ void pulsein_reset(void);
 
 void pulsein_interrupt_handler(uint8_t channel);
 void pulsein_timer_interrupt_handler(uint8_t index);
+void update_background_ticks(void);
 #ifdef SAMD21
 void rtc_set_continuous(void);
 void rtc_start_pulsein(void);

supervisor/shared/background_callback.c

@@ -37,12 +37,16 @@ STATIC volatile background_callback_t *callback_head, *callback_tail;
 #define CALLBACK_CRITICAL_BEGIN (common_hal_mcu_disable_interrupts())
 #define CALLBACK_CRITICAL_END (common_hal_mcu_enable_interrupts())
 
-volatile uint64_t last_background_tick = 0;
+uint64_t last_background_tick = 0;
 
 uint64_t get_background_ticks(void) {
     return last_background_tick;
 }
 
+void update_background_ticks(void) {
+    last_background_tick = port_get_raw_ticks(NULL);
+}
+
 void background_callback_add_core(background_callback_t *cb) {
     CALLBACK_CRITICAL_BEGIN;
     if (cb->prev || callback_head == cb) {