Update default features to empty

lvgl/Cargo.toml

@@ -21,6 +21,7 @@ parking_lot = "0.11.1"
 heapless = "0.7.1"
 
 [features]
+default = []
 alloc = ["cstr_core/alloc"]
 lvgl_alloc = ["alloc"]
 

lvgl/src/display.rs

@@ -101,6 +101,9 @@ impl<const N: usize> DrawBuffer<N> {
 
     fn get_ptr(&self) -> Option<Box<lvgl_sys::lv_disp_buf_t>> {
         if self.initialized.swap_and_check() {
+            // TODO: needs to be 'static somehow
+            // Cannot be in the DrawBuffer struct because the type `lv_disp_buf_t` contains a raw
+            // pointer and raw pointers are not Sync and consequently cannot be in `static` variables.
             let mut inner: MaybeUninit<lvgl_sys::lv_disp_buf_t> = MaybeUninit::uninit();
             let primary_buffer_guard = self.refresh_buffer.lock();
             let draw_buf = unsafe {

lvgl/src/functions.rs

@@ -14,7 +14,7 @@ pub enum CoreError {
 type Result<T> = result::Result<T, CoreError>;
 
 /// Register own buffer
-pub fn disp_drv_register<C: PixelColor + From<Color>, T: DrawTarget<C>>(
+pub(crate) fn disp_drv_register<C: PixelColor + From<Color>, T: DrawTarget<C>>(
     disp_drv: &mut DisplayDriver<T, C>,
 ) -> Result<Display> {
     let disp_ptr = unsafe { lvgl_sys::lv_disp_drv_register(&mut disp_drv.disp_drv as *mut _) };