Workaround for Linux build getting black screen on some computers.

See issue for more details zephyrproject-rtos/zephyr#71410
Workaround is to run lv_task_handler from main thread and disable CONFIG_LV_Z_FLUSH_THREAD.

app/boards/native_posix.conf

@@ -53,3 +53,4 @@ CONFIG_SPI_FLASH_LOADER=n
 CONFIG_BT_EXT_ADV=n
 
 CONFIG_SDL_DISPLAY_ZOOM_PCT=200
+CONFIG_LV_Z_FLUSH_THREAD=n

app/src/drivers/zsw_display_control.c

@@ -262,12 +262,16 @@ void zsw_display_control_set_brightness(uint8_t percent)
 
 static void lvgl_render(struct k_work *item)
 {
+    // Workaround due to https://github.com/zephyrproject-rtos/zephyr/issues/71410
+    // we need to run lv_task_handler from main thread and disable CONFIG_LV_Z_FLUSH_THREAD
+#ifndef CONFIG_BOARD_NATIVE_POSIX
     const int64_t next_update_in_ms = lv_task_handler();
     if (first_render_since_poweron) {
         zsw_display_control_set_brightness(last_brightness);
         first_render_since_poweron = false;
     }
     k_work_schedule(&lvgl_work, K_MSEC(next_update_in_ms));
+#endif
 }
 
 static void set_brightness_level(uint8_t brightness)

app/src/main.c

@@ -297,6 +297,16 @@ int main(void)
     // it has the required amount of stack.
     k_work_submit(&init_work);
 
+    // Workaround due to https://github.com/zephyrproject-rtos/zephyr/issues/71410
+    // we need to run lv_task_handler from main thread and disable CONFIG_LV_Z_FLUSH_THREAD
+#ifdef CONFIG_BOARD_NATIVE_POSIX
+    int64_t next_update_in_ms;
+    while (true) {
+        next_update_in_ms = lv_task_handler();
+        k_msleep(next_update_in_ms);
+    }
+#endif
+
     return 0;
 }