Fix for I2S noise burst when ESP32 panic occurs (#437)

components/_override/esp32/i2s.c

@@ -705,6 +705,26 @@ esp_err_t i2s_stop(i2s_port_t i2s_num)
     return ESP_OK;
 }
 
+/* 
+ * When a panic occurs during playback, the I2S interface can produce a loud noise burst.
+ * This code runs just before the system panic handler to "emergency stop" the I2S iterface
+ * to prevent the noise burst from happening.  Note that when this code is called the system
+ * has already crashed, so no need to disable interrupts, acquire locks, or otherwise be nice.
+ *
+ * This code makes use of the linker --wrap feature to intercept the call to esp_panic_handler.
+ */
+
+void __real_esp_panic_handler(void*);
+
+void __wrap_esp_panic_handler (void* info) {
+    esp_rom_printf("I2S abort!\r\n");
+    
+    i2s_hal_stop_tx(&(p_i2s_obj[CONFIG_I2S_NUM]->hal));
+    
+    /* Call the original panic handler function to finish processing this error */
+    __real_esp_panic_handler(info);
+}
+
 #if SOC_I2S_SUPPORTS_ADC_DAC
 esp_err_t i2s_set_dac_mode(i2s_dac_mode_t dac_mode)
 {