diff --git a/arch/arm/src/at32/at32_rtc_lowerhalf.c b/arch/arm/src/at32/at32_rtc_lowerhalf.c
index b23e1861159f6..b9eb5974c856c 100644
--- a/arch/arm/src/at32/at32_rtc_lowerhalf.c
+++ b/arch/arm/src/at32/at32_rtc_lowerhalf.c
@@ -511,6 +511,7 @@ static int at32_setrelative(struct rtc_lowerhalf_s *lower,
   struct tm time;
   time_t seconds;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL);
   DEBUGASSERT(alarminfo->id == RTC_ALARMA || alarminfo->id == RTC_ALARMB);
@@ -522,7 +523,7 @@ static int at32_setrelative(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
       /* Get the current time in broken out format */
 
@@ -552,7 +553,7 @@ static int at32_setrelative(struct rtc_lowerhalf_s *lower,
           ret = at32_setalarm(lower, &setalarm);
         }
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
@@ -565,6 +566,7 @@ static int at32_setrelative(struct rtc_lowerhalf_s *lower,
 #endif
   struct timespec ts;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL && alarminfo->id == 0);
   priv = (struct at32_lowerhalf_s *)lower;
@@ -575,7 +577,7 @@ static int at32_setrelative(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
       /* Get the current time in seconds */
 
@@ -585,7 +587,7 @@ static int at32_setrelative(struct rtc_lowerhalf_s *lower,
       ret = up_rtc_getdatetime(&time);
       if (ret < 0)
         {
-          sched_unlock();
+          leave_critical_section(flags);
           return ret;
         }
 
@@ -598,7 +600,7 @@ static int at32_setrelative(struct rtc_lowerhalf_s *lower,
       ret = up_rtc_gettime(&ts);
       if (ret < 0)
         {
-          sched_unlock();
+          leave_critical_section(flags);
           return ret;
         }
 #else
@@ -629,7 +631,7 @@ static int at32_setrelative(struct rtc_lowerhalf_s *lower,
           cbinfo->priv = NULL;
         }
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
@@ -734,6 +736,7 @@ static int at32_rdalarm(struct rtc_lowerhalf_s *lower,
 {
   struct alm_rdalarm_s lowerinfo;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL && alarminfo->time != NULL);
   DEBUGASSERT(alarminfo->id == RTC_ALARMA || alarminfo->id == RTC_ALARMB);
@@ -744,14 +747,14 @@ static int at32_rdalarm(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
       lowerinfo.ar_id   = alarminfo->id;
       lowerinfo.ar_time = alarminfo->time;
 
       ret = at32_rtc_rdalarm(&lowerinfo);
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
diff --git a/arch/arm/src/cxd56xx/cxd56_rtc_lowerhalf.c b/arch/arm/src/cxd56xx/cxd56_rtc_lowerhalf.c
index abfc7a7e2e041..618427d3f3a7c 100644
--- a/arch/arm/src/cxd56xx/cxd56_rtc_lowerhalf.c
+++ b/arch/arm/src/cxd56xx/cxd56_rtc_lowerhalf.c
@@ -361,6 +361,7 @@ static int cxd56_setrelative(struct rtc_lowerhalf_s *lower,
   struct timespec ts;
   time_t seconds;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL);
   DEBUGASSERT((RTC_ALARM0 <= alarminfo->id) &&
@@ -372,7 +373,7 @@ static int cxd56_setrelative(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
 #if defined(CONFIG_RTC_HIRES)
       /* Get the higher resolution time */
@@ -380,7 +381,7 @@ static int cxd56_setrelative(struct rtc_lowerhalf_s *lower,
       ret = up_rtc_gettime(&ts);
       if (ret < 0)
         {
-          sched_unlock();
+          leave_critical_section(flags);
           return ret;
         }
 #else
@@ -406,7 +407,7 @@ static int cxd56_setrelative(struct rtc_lowerhalf_s *lower,
 
       ret = cxd56_setalarm(lower, &setalarm);
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
diff --git a/arch/arm/src/kinetis/kinetis_rtc_lowerhalf.c b/arch/arm/src/kinetis/kinetis_rtc_lowerhalf.c
index 65676fcf59fa1..ef596268ad65a 100644
--- a/arch/arm/src/kinetis/kinetis_rtc_lowerhalf.c
+++ b/arch/arm/src/kinetis/kinetis_rtc_lowerhalf.c
@@ -363,6 +363,7 @@ kinetis_setrelative(struct rtc_lowerhalf_s *lower,
   time_t seconds;
   struct timespec ts;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL);
   DEBUGASSERT(alarminfo->id == RTC_ALARMA);
@@ -374,7 +375,7 @@ kinetis_setrelative(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
 #if defined(CONFIG_RTC_DATETIME)
       /* Get the broken out time and convert to seconds */
@@ -382,7 +383,7 @@ kinetis_setrelative(struct rtc_lowerhalf_s *lower,
       ret = up_rtc_getdatetime(&time);
       if (ret < 0)
         {
-          sched_unlock();
+          leave_critical_section(flags);
           return ret;
         }
 
@@ -394,7 +395,7 @@ kinetis_setrelative(struct rtc_lowerhalf_s *lower,
       ret = up_rtc_gettime(&ts);
       if (ret < 0)
         {
-          sched_unlock();
+          leave_critical_section(flags);
           return ret;
         }
 #endif
@@ -421,7 +422,7 @@ kinetis_setrelative(struct rtc_lowerhalf_s *lower,
 
       ret = kinetis_setalarm(lower, &setalarm);
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
@@ -498,6 +499,7 @@ static int kinetis_rdalarm(struct rtc_lowerhalf_s *lower,
 {
   struct timespec ts;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL && alarminfo->time != NULL);
   DEBUGASSERT(alarminfo->id == RTC_ALARMA);
@@ -508,12 +510,12 @@ static int kinetis_rdalarm(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
       ret = kinetis_rtc_rdalarm(&ts);
 
       localtime_r((const time_t *)&ts.tv_sec,
                   (struct tm *)alarminfo->time);
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
diff --git a/arch/arm/src/lpc54xx/lpc54_rtc_lowerhalf.c b/arch/arm/src/lpc54xx/lpc54_rtc_lowerhalf.c
index 51ef847136a84..2a91635b1b107 100644
--- a/arch/arm/src/lpc54xx/lpc54_rtc_lowerhalf.c
+++ b/arch/arm/src/lpc54xx/lpc54_rtc_lowerhalf.c
@@ -365,6 +365,7 @@ static int lpc54_setrelative(struct rtc_lowerhalf_s *lower,
   struct lpc54_cbinfo_s *cbinfo;
   struct timespec ts;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL && alarminfo->id == 0);
   priv = (struct lpc54_lowerhalf_s *)lower;
@@ -375,7 +376,7 @@ static int lpc54_setrelative(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
       /* Get the current time in seconds */
 
@@ -403,7 +404,7 @@ static int lpc54_setrelative(struct rtc_lowerhalf_s *lower,
           cbinfo->priv = NULL;
         }
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
diff --git a/arch/arm/src/max326xx/common/max326_rtc_lowerhalf.c b/arch/arm/src/max326xx/common/max326_rtc_lowerhalf.c
index 2f8c993c798ce..c9e855629e87a 100644
--- a/arch/arm/src/max326xx/common/max326_rtc_lowerhalf.c
+++ b/arch/arm/src/max326xx/common/max326_rtc_lowerhalf.c
@@ -430,6 +430,7 @@ static int max326_setrelative(struct rtc_lowerhalf_s *lower,
 #endif
   struct timespec ts;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL && alarminfo->id == 0);
   priv = (struct max326_lowerhalf_s *)lower;
@@ -440,7 +441,7 @@ static int max326_setrelative(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
       /* Get the current time in seconds */
 
@@ -450,7 +451,7 @@ static int max326_setrelative(struct rtc_lowerhalf_s *lower,
       ret = up_rtc_getdatetime(&time);
       if (ret < 0)
         {
-          sched_unlock();
+          leave_critical_section(flags);
           return ret;
         }
 
@@ -463,7 +464,7 @@ static int max326_setrelative(struct rtc_lowerhalf_s *lower,
       ret = up_rtc_gettime(&ts);
       if (ret < 0)
         {
-          sched_unlock();
+          leave_critical_section(flags);
           return ret;
         }
 #else
@@ -494,7 +495,7 @@ static int max326_setrelative(struct rtc_lowerhalf_s *lower,
           cbinfo->priv = NULL;
         }
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
diff --git a/arch/arm/src/stm32/stm32_rtc_lowerhalf.c b/arch/arm/src/stm32/stm32_rtc_lowerhalf.c
index 0f277c8fc86d7..2daa841299321 100644
--- a/arch/arm/src/stm32/stm32_rtc_lowerhalf.c
+++ b/arch/arm/src/stm32/stm32_rtc_lowerhalf.c
@@ -515,6 +515,7 @@ static int stm32_setrelative(struct rtc_lowerhalf_s *lower,
   struct tm time;
   time_t seconds;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL);
   DEBUGASSERT(alarminfo->id == RTC_ALARMA || alarminfo->id == RTC_ALARMB);
@@ -526,7 +527,7 @@ static int stm32_setrelative(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
       /* Get the current time in broken out format */
 
@@ -556,7 +557,7 @@ static int stm32_setrelative(struct rtc_lowerhalf_s *lower,
           ret = stm32_setalarm(lower, &setalarm);
         }
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
@@ -569,6 +570,7 @@ static int stm32_setrelative(struct rtc_lowerhalf_s *lower,
 #endif
   struct timespec ts;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL && alarminfo->id == 0);
   priv = (struct stm32_lowerhalf_s *)lower;
@@ -579,7 +581,7 @@ static int stm32_setrelative(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
       /* Get the current time in seconds */
 
@@ -589,7 +591,7 @@ static int stm32_setrelative(struct rtc_lowerhalf_s *lower,
       ret = up_rtc_getdatetime(&time);
       if (ret < 0)
         {
-          sched_unlock();
+          leave_critical_section(flags);
           return ret;
         }
 
@@ -602,7 +604,7 @@ static int stm32_setrelative(struct rtc_lowerhalf_s *lower,
       ret = up_rtc_gettime(&ts);
       if (ret < 0)
         {
-          sched_unlock();
+          leave_critical_section(flags);
           return ret;
         }
 #else
@@ -633,7 +635,7 @@ static int stm32_setrelative(struct rtc_lowerhalf_s *lower,
           cbinfo->priv = NULL;
         }
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
@@ -738,6 +740,7 @@ static int stm32_rdalarm(struct rtc_lowerhalf_s *lower,
 {
   struct alm_rdalarm_s lowerinfo;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL && alarminfo->time != NULL);
   DEBUGASSERT(alarminfo->id == RTC_ALARMA || alarminfo->id == RTC_ALARMB);
@@ -748,14 +751,14 @@ static int stm32_rdalarm(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
       lowerinfo.ar_id   = alarminfo->id;
       lowerinfo.ar_time = alarminfo->time;
 
       ret = stm32_rtc_rdalarm(&lowerinfo);
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
diff --git a/arch/arm/src/stm32f7/stm32_rtc_lowerhalf.c b/arch/arm/src/stm32f7/stm32_rtc_lowerhalf.c
index af26ba0a1f7c3..6f7c88b995bee 100644
--- a/arch/arm/src/stm32f7/stm32_rtc_lowerhalf.c
+++ b/arch/arm/src/stm32f7/stm32_rtc_lowerhalf.c
@@ -433,6 +433,7 @@ static int stm32_setrelative(struct rtc_lowerhalf_s *lower,
   struct tm time;
   time_t seconds;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL);
   DEBUGASSERT(alarminfo->id == RTC_ALARMA || alarminfo->id == RTC_ALARMB);
@@ -444,7 +445,7 @@ static int stm32_setrelative(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
       /* Get the current time in broken out format */
 
@@ -474,7 +475,7 @@ static int stm32_setrelative(struct rtc_lowerhalf_s *lower,
           ret = stm32_setalarm(lower, &setalarm);
         }
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
@@ -558,6 +559,7 @@ static int stm32_rdalarm(struct rtc_lowerhalf_s *lower,
 {
   struct alm_rdalarm_s lowerinfo;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL && alarminfo->time != NULL);
   DEBUGASSERT(alarminfo->id == RTC_ALARMA || alarminfo->id == RTC_ALARMB);
@@ -568,14 +570,14 @@ static int stm32_rdalarm(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
       lowerinfo.ar_id = alarminfo->id;
       lowerinfo.ar_time = alarminfo->time;
 
       ret = stm32_rtc_rdalarm(&lowerinfo);
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
diff --git a/arch/arm/src/stm32h7/stm32_rtc_lowerhalf.c b/arch/arm/src/stm32h7/stm32_rtc_lowerhalf.c
index 490c4df83f36a..6eeecf314eb5e 100644
--- a/arch/arm/src/stm32h7/stm32_rtc_lowerhalf.c
+++ b/arch/arm/src/stm32h7/stm32_rtc_lowerhalf.c
@@ -434,6 +434,7 @@ static int stm32_setrelative(struct rtc_lowerhalf_s *lower,
   struct tm time;
   time_t seconds;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL);
   DEBUGASSERT(alarminfo->id == RTC_ALARMA || alarminfo->id == RTC_ALARMB);
@@ -445,7 +446,7 @@ static int stm32_setrelative(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
       /* Get the current time in broken out format */
 
@@ -475,7 +476,7 @@ static int stm32_setrelative(struct rtc_lowerhalf_s *lower,
           ret = stm32_setalarm(lower, &setalarm);
         }
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
@@ -559,6 +560,7 @@ static int stm32_rdalarm(struct rtc_lowerhalf_s *lower,
 {
   struct alm_rdalarm_s lowerinfo;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL && alarminfo->time != NULL);
   DEBUGASSERT(alarminfo->id == RTC_ALARMA || alarminfo->id == RTC_ALARMB);
@@ -569,14 +571,14 @@ static int stm32_rdalarm(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
       lowerinfo.ar_id = alarminfo->id;
       lowerinfo.ar_time = alarminfo->time;
 
       ret = stm32_rtc_rdalarm(&lowerinfo);
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
diff --git a/arch/arm/src/stm32l4/stm32l4_rtc_lowerhalf.c b/arch/arm/src/stm32l4/stm32l4_rtc_lowerhalf.c
index 70275bfabab89..a56201a6d2623 100644
--- a/arch/arm/src/stm32l4/stm32l4_rtc_lowerhalf.c
+++ b/arch/arm/src/stm32l4/stm32l4_rtc_lowerhalf.c
@@ -399,6 +399,7 @@ stm32l4_setrelative(struct rtc_lowerhalf_s *lower,
   struct tm time;
   time_t seconds;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL);
   DEBUGASSERT(alarminfo->id == RTC_ALARMA || alarminfo->id == RTC_ALARMB);
@@ -410,7 +411,7 @@ stm32l4_setrelative(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
       /* Get the current time in broken out format */
 
@@ -440,7 +441,7 @@ stm32l4_setrelative(struct rtc_lowerhalf_s *lower,
           ret = stm32l4_setalarm(lower, &setalarm);
         }
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
@@ -525,6 +526,7 @@ static int stm32l4_rdalarm(struct rtc_lowerhalf_s *lower,
 {
   struct alm_rdalarm_s lowerinfo;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL && alarminfo->time != NULL);
   DEBUGASSERT(alarminfo->id == RTC_ALARMA || alarminfo->id == RTC_ALARMB);
@@ -535,14 +537,14 @@ static int stm32l4_rdalarm(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
       lowerinfo.ar_id = alarminfo->id;
       lowerinfo.ar_time = alarminfo->time;
 
       ret = stm32l4_rtc_rdalarm(&lowerinfo);
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
diff --git a/arch/arm/src/stm32wb/stm32wb_rtc_lowerhalf.c b/arch/arm/src/stm32wb/stm32wb_rtc_lowerhalf.c
index d5e582e9025aa..fd2b51cb74120 100644
--- a/arch/arm/src/stm32wb/stm32wb_rtc_lowerhalf.c
+++ b/arch/arm/src/stm32wb/stm32wb_rtc_lowerhalf.c
@@ -398,6 +398,7 @@ stm32wb_setrelative(struct rtc_lowerhalf_s *lower,
   struct tm time;
   time_t seconds;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL);
   DEBUGASSERT(alarminfo->id == RTC_ALARMA || alarminfo->id == RTC_ALARMB);
@@ -409,7 +410,7 @@ stm32wb_setrelative(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
       /* Get the current time in broken out format */
 
@@ -439,7 +440,7 @@ stm32wb_setrelative(struct rtc_lowerhalf_s *lower,
           ret = stm32wb_setalarm(lower, &setalarm);
         }
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
@@ -523,6 +524,7 @@ static int stm32wb_rdalarm(struct rtc_lowerhalf_s *lower,
 {
   struct alm_rdalarm_s lowerinfo;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL && alarminfo->time != NULL);
   DEBUGASSERT(alarminfo->id == RTC_ALARMA || alarminfo->id == RTC_ALARMB);
@@ -533,14 +535,14 @@ static int stm32wb_rdalarm(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
       lowerinfo.ar_id = alarminfo->id;
       lowerinfo.ar_time = alarminfo->time;
 
       ret = stm32wb_rtc_rdalarm(&lowerinfo);
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
diff --git a/arch/renesas/src/rx65n/rx65n_rtc_lowerhalf.c b/arch/renesas/src/rx65n/rx65n_rtc_lowerhalf.c
index 05d269427ab67..af8eca502122a 100644
--- a/arch/renesas/src/rx65n/rx65n_rtc_lowerhalf.c
+++ b/arch/renesas/src/rx65n/rx65n_rtc_lowerhalf.c
@@ -416,6 +416,7 @@ static int rx65n_setrelative(struct rtc_lowerhalf_s *lower,
   struct timespec rtc_time;
   time_t seconds;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL);
 
@@ -425,7 +426,7 @@ static int rx65n_setrelative(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
 #if defined(CONFIG_RTC_DATETIME)
       /* Get the broken out time and convert to seconds */
@@ -434,7 +435,7 @@ static int rx65n_setrelative(struct rtc_lowerhalf_s *lower,
       ret = up_rtc_getdatetime(&time);
       if (ret < 0)
         {
-          sched_unlock();
+          leave_critical_section(flags);
           return ret;
         }
 
@@ -478,7 +479,7 @@ static int rx65n_setrelative(struct rtc_lowerhalf_s *lower,
 
       /* Remember the callback information */
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
@@ -546,6 +547,7 @@ static int rx65n_rdalarm(struct rtc_lowerhalf_s *lower,
 {
   struct alm_rdalarm_s lowerinfo;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL && alarminfo->time != NULL);
   if (alarminfo->id >= 0)
@@ -554,14 +556,14 @@ static int rx65n_rdalarm(struct rtc_lowerhalf_s *lower,
        * about being suspended and working on an old time.
        */
 
-      sched_lock();
+      flags = enter_critical_section();
 
       lowerinfo.ar_id = alarminfo->id;
       lowerinfo.ar_time = alarminfo->time;
 
       ret = rx65n_rtc_rdalarm(&lowerinfo);
 
-      sched_unlock();
+      leave_critical_section(flags);
     }
 
   return ret;
diff --git a/arch/z80/src/ez80/ez80_rtc_lowerhalf.c b/arch/z80/src/ez80/ez80_rtc_lowerhalf.c
index daba8401efde5..dfec0a29843be 100644
--- a/arch/z80/src/ez80/ez80_rtc_lowerhalf.c
+++ b/arch/z80/src/ez80/ez80_rtc_lowerhalf.c
@@ -405,6 +405,7 @@ static int ez80_setrelative(FAR struct rtc_lowerhalf_s *lower,
   struct tm time;
   time_t seconds;
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL && alarminfo->id == 0);
 
@@ -412,7 +413,7 @@ static int ez80_setrelative(FAR struct rtc_lowerhalf_s *lower,
    * about being suspended and working on an old time.
    */
 
-  sched_lock();
+  flags = enter_critical_section();
 
   /* Get the current time in broken out format */
 
@@ -441,7 +442,7 @@ static int ez80_setrelative(FAR struct rtc_lowerhalf_s *lower,
       ret = ez80_setalarm(lower, &setalarm);
     }
 
-  sched_unlock();
+  leave_critical_section(flags);
   return ret;
 }
 #endif
@@ -516,6 +517,7 @@ static int ez80_rdalarm(FAR struct rtc_lowerhalf_s *lower,
                         FAR struct lower_rdalarm_s *alarminfo)
 {
   int ret = -EINVAL;
+  irqstate_t flags;
 
   DEBUGASSERT(lower != NULL && alarminfo != NULL &&
               alarminfo->time != NULL && alarminfo->id == 0);
@@ -524,9 +526,9 @@ static int ez80_rdalarm(FAR struct rtc_lowerhalf_s *lower,
    * about being suspended and working on an old time.
    */
 
-  sched_lock();
+  flags = enter_critical_section();
   ret = ez80_rtc_rdalarm((FAR struct tm *)alarminfo->time);
-  sched_unlock();
+  leave_critical_section(flags);
 
   return ret;
 }