Revert "fix(flush,tick): use atomics instead of volatile for synchronization (#3965)" (#3997)

src/hal/lv_hal_disp.h

@@ -23,11 +23,6 @@ extern "C" {
 #include "../misc/lv_area.h"
 #include "../misc/lv_ll.h"
 #include "../misc/lv_timer.h"
-#include "../misc/lv_types.h"
-
-#if LV_USE_ATOMICS == 1
-#include <stdatomic.h>
-#endif
 
 /*********************
  *      DEFINES
@@ -52,11 +47,6 @@ struct _lv_disp_t;
 struct _lv_disp_drv_t;
 struct _lv_theme_t;
 
-#if LV_USE_ATOMICS == 1
-#define FLUSHING_TYPE atomic_int
-#else
-#define FLUSHING_TYPE volatile int
-#endif
 /**
  * Structure for holding display buffer information.
  */
@@ -67,13 +57,13 @@ typedef struct _lv_disp_draw_buf_t {
     /*Internal, used by the library*/
     void * buf_act;
     uint32_t size; /*In pixel count*/
-    FLUSHING_TYPE flushing;
+    /*1: flushing is in progress. (It can't be a bit field because when it's cleared from IRQ Read-Modify-Write issue might occur)*/
-    /*It was the last chunk to flush. (It can't be a bit field because when it's cleared from IRQ Read-Modify-Write issue might occur)*/
+    volatile int flushing;
-    FLUSHING_TYPE flushing_last;
+    /*1: It was the last chunk to flush. (It can't be a bit field because when it's cleared from IRQ Read-Modify-Write issue might occur)*/
-    uint32_t last_area         : 1; /*1: the last area is being rendered*/
+    volatile int flushing_last;
-    uint32_t last_part         : 1; /*1: the last part of the current area is being rendered*/
+    volatile uint32_t last_area         : 1; /*1: the last area is being rendered*/
+    volatile uint32_t last_part         : 1; /*1: the last part of the current area is being rendered*/
 } lv_disp_draw_buf_t;
-#undef FLUSHING_TYPE
 
 typedef enum {
     LV_DISP_ROT_NONE = 0,

src/hal/lv_hal_tick.c

@@ -7,8 +7,6 @@
  *      INCLUDES
  *********************/
 #include "lv_hal_tick.h"
-#include "../misc/lv_types.h"
-#include <stdatomic.h>
 #include <stddef.h>
 
 #if LV_TICK_CUSTOM == 1
@@ -31,13 +29,8 @@
  *  STATIC VARIABLES
  **********************/
 #if !LV_TICK_CUSTOM
-    #if LV_USE_ATOMICS == 1
+    static uint32_t sys_time = 0;
-        static _Atomic(uint32_t) sys_time = 0;
+    static volatile uint8_t tick_irq_flag;
-        static atomic_int tick_irq_flag;
-    #else
-        static volatile uint32_t sys_time = 0;
-        static volatile int tick_irq_flag;
-    #endif
 #endif
 
 /**********************

src/misc/lv_types.h

@@ -32,15 +32,6 @@ extern "C" {
 
 #endif
 
-/*Use atomics instead of volatile variables for state which is potentially shared between threads, as long as
- *the compiler supports it.*/
-#if (defined(__cplusplus) && __cplusplus >= 201103L)\
-    || (__STDC_VERSION__ >= 201112L && !defined(__STDC_NO_ATOMICS__))
-#define LV_USE_ATOMICS 1
-#else
-#define LV_USE_ATOMICS 0
-#endif
-
 /**********************
  *      TYPEDEFS
  **********************/