Reduce clock before resetting core1

display.cpp

@@ -241,6 +241,8 @@ void DisplayDriver::run() {
             }
         }
 
+        //pwm_set_gpio_level(PIN_LED, frame_data.frame_table_header.bank_number ? 255*255 : 0);
+
         frame_data.get_frame_table(frame_counter, frame_table);
 
         if (frame_data.config.v_repeat != dvi0.vertical_repeat) {
@@ -365,8 +367,6 @@ void DisplayDriver::run() {
         clear_sprite(i);
     }
 
-    multicore_reset_core1();
-
     if (heartbet_led) {
         pwm_set_gpio_level(PIN_LED, 0);
     }

main.cpp

@@ -14,6 +14,7 @@
 #include "hardware/structs/pads_qspi.h"
 #include "hardware/structs/ioqspi.h"
 #include "hardware/adc.h"
+#include "pico/multicore.h"
 
 #include "i2c_interface.hpp"
 #include "display.hpp"
@@ -373,6 +374,21 @@ int main() {
 
         display.run();
 
+        // Set the clock rate back down to 125MHz.
+        // It appears that weird stuff happens if we try to reset core 1
+        // while running at 400MHz!!
+
+        // Deinit I2C before adjusting clock
+        i2c_slave_if::deinit();
+
+        set_sys_clock_khz(125000, true);
+
+        stdio_init_all();
+        multicore_reset_core1();
+
+        // Reinit I2C now clock is set.
+        i2c_slave_if::init(handle_i2c_sprite_write, handle_i2c_reg_write);
+
         printf("DV Driver: Display stopped\n");
         regs[0xFD] = 0;
     }