Tweaked to run without delays on zero w

Author: RetiredWizard

ports/broadcom/common-hal/neopixel_write/__init__.c

@@ -97,6 +97,7 @@ void common_hal_neopixel_write(const digitalio_digitalinout_obj_t *digitalinout,
         COMPLETE_MEMORY_READS;
         icnt = 0;
         while ((CM_PWM->CS_b.BUSY == 0) & (icnt++ < 1000)) {
+            COMPLETE_MEMORY_READS;
         }
     }
 
@@ -142,19 +143,22 @@ void common_hal_neopixel_write(const digitalio_digitalinout_obj_t *digitalinout,
             icnt = 0;
             while ((pwm->STA_b.FULL1 == 1) & (icnt++ < 150)) {
                 RUN_BACKGROUND_TASKS;
+                COMPLETE_MEMORY_READS;
             }
             // Dummy value for the first channel.
             pwm->FIF1 = 0x000000;
         }
         icnt = 0;
         while ((pwm->STA_b.FULL1 == 1) & (icnt++ < 150)) {
             RUN_BACKGROUND_TASKS;
+            COMPLETE_MEMORY_READS;
         }
         pwm->FIF1 = expanded;
         if (channel == 0) {
             icnt = 0;
             while ((pwm->STA_b.FULL1 == 1) & (icnt++ < 150)) {
                 RUN_BACKGROUND_TASKS;
+                COMPLETE_MEMORY_READS;
             }
             // Dummy value for the second channel.
             pwm->FIF1 = 0x000000;
@@ -164,17 +168,23 @@ void common_hal_neopixel_write(const digitalio_digitalinout_obj_t *digitalinout,
     icnt = 0;
     while ((pwm->STA_b.EMPT1 == 0) & (icnt++ < 2500)) {
         RUN_BACKGROUND_TASKS;
+        COMPLETE_MEMORY_READS;
     }
     // Wait for transmission to start.
     icnt = 0;
     while (((pwm->STA_b.STA1 == 0) & (pwm->STA_b.STA2 == 0)) & (icnt++ < 150)) {
         RUN_BACKGROUND_TASKS;
+        COMPLETE_MEMORY_READS;
     }
     // Wait for transmission to complete.
     icnt = 0;
     while (((pwm->STA_b.STA1 == 1) | (pwm->STA_b.STA2 == 1)) & (icnt++ < 150)) {
         RUN_BACKGROUND_TASKS;
+        COMPLETE_MEMORY_READS;
     }
+    // Shouldn't be anything left in queue but clear it so the clock doesn't crash if there is
+    pwm->CTL = PWM0_CTL_CLRF1_Msk;
+    COMPLETE_MEMORY_READS;
 
     gpio_set_function(digitalinout->pin->number, GPIO_FUNCTION_OUTPUT);