Remove support for busy-wait millisecond delays with IRQs disabled

bricks/_common_stm32/mphalport.c

@@ -22,22 +22,17 @@
 extern volatile uint32_t pbdrv_clock_ticks;
 
 // Core delay function that does an efficient sleep and may switch thread context.
-// If IRQs are enabled then we must have the GIL.
+// We must have the GIL.
 void mp_hal_delay_ms(mp_uint_t Delay) {
-    if (pbdrv_clock_is_ticking()) {
-        // IRQs enabled, so can use systick counter to do the delay
-        uint32_t start = pbdrv_clock_ticks;
-        // Wraparound of tick is taken care of by 2's complement arithmetic.
-        do {
-            // This macro will execute the necessary idle behaviour.  It may
-            // raise an exception, switch threads or enter sleep mode (waiting for
-            // (at least) the SysTick interrupt).
-            MICROPY_EVENT_POLL_HOOK
-        } while (pbdrv_clock_ticks - start < Delay);
-    } else {
-        // IRQs disabled, so need to use a busy loop for the delay.
-        pbdrv_clock_busy_delay_ms(Delay);
-    }
+    // Use systick counter to do the delay
+    uint32_t start = pbdrv_clock_ticks;
+    // Wraparound of tick is taken care of by 2's complement arithmetic.
+    do {
+        // This macro will execute the necessary idle behaviour.  It may
+        // raise an exception, switch threads or enter sleep mode (waiting for
+        // (at least) the SysTick interrupt).
+        MICROPY_EVENT_POLL_HOOK
+    } while (pbdrv_clock_ticks - start < Delay);
 }
 
 uintptr_t mp_hal_stdio_poll(uintptr_t poll_flags) {

bricks/ev3/mphalport.c

@@ -19,9 +19,9 @@
 #include "py/stream.h"
 
 // Core delay function that does an efficient sleep and may switch thread context.
-// If IRQs are enabled then we must have the GIL.
+// We must have the GIL.
 void mp_hal_delay_ms(mp_uint_t Delay) {
-    // IRQs enabled, so can use systick counter to do the delay
+    // Use systick counter to do the delay
     uint32_t start = pbdrv_clock_get_ms();
     // Wraparound of tick is taken care of by 2's complement arithmetic.
     do {

bricks/nxt/mphalport.c

@@ -18,28 +18,18 @@
 #include "py/mpconfig.h"
 #include "py/stream.h"
 
-// TODO
-static bool interrupts_get(void) {
-    return true;
-}
-
 // Core delay function that does an efficient sleep and may switch thread context.
-// If IRQs are enabled then we must have the GIL.
+// We must have the GIL.
 void mp_hal_delay_ms(mp_uint_t Delay) {
-    if (interrupts_get()) {
-        // IRQs enabled, so can use systick counter to do the delay
-        uint32_t start = pbdrv_clock_get_ms();
-        // Wraparound of tick is taken care of by 2's complement arithmetic.
-        do {
-            // This macro will execute the necessary idle behaviour.  It may
-            // raise an exception, switch threads or enter sleep mode (waiting for
-            // (at least) the SysTick interrupt).
-            MICROPY_EVENT_POLL_HOOK
-        } while (pbdrv_clock_get_ms() - start < Delay);
-    } else {
-        // IRQs disabled, so need to use a busy loop for the delay.
-        nx_systick_wait_ms(Delay);
-    }
+    // Use systick counter to do the delay
+    uint32_t start = pbdrv_clock_get_ms();
+    // Wraparound of tick is taken care of by 2's complement arithmetic.
+    do {
+        // This macro will execute the necessary idle behaviour.  It may
+        // raise an exception, switch threads or enter sleep mode (waiting for
+        // (at least) the SysTick interrupt).
+        MICROPY_EVENT_POLL_HOOK
+    } while (pbdrv_clock_get_ms() - start < Delay);
 }
 
 // delay for given number of microseconds

lib/pbio/drv/clock/clock_ev3.c

@@ -119,13 +119,4 @@ uint32_t pbdrv_clock_get_100us(void) {
     return pbdrv_clock_get_ms() * 10;
 }
 
-void pbdrv_clock_busy_delay_ms(uint32_t ms) {
-    // TODO
-}
-
-bool pbdrv_clock_is_ticking(void) {
-    // TODO
-    return true;
-}
-
 #endif // PBDRV_CONFIG_CLOCK_TIAM1808

lib/pbio/drv/clock/clock_linux.c

@@ -112,14 +112,4 @@ uint32_t pbdrv_clock_get_us(void) {
     return time_val.tv_sec * 1000000 + time_val.tv_nsec / 1000;
 }
 
-void pbdrv_clock_busy_delay_ms(uint32_t ms) {
-    uint32_t start = pbdrv_clock_get_ms();
-    while (pbdrv_clock_get_ms() - start < ms) {
-    }
-}
-
-bool pbdrv_clock_is_ticking(void) {
-    return true;
-}
-
 #endif // PBDRV_CONFIG_CLOCK_LINUX

lib/pbio/drv/clock/clock_none.c

@@ -22,11 +22,4 @@ uint32_t pbdrv_clock_get_100us(void) {
     return 0;
 }
 
-void pbdrv_clock_busy_delay_ms(uint32_t ms) {
-}
-
-bool pbdrv_clock_is_ticking(void) {
-    return false;
-}
-
 #endif // PBDRV_CONFIG_CLOCK_NONE

lib/pbio/drv/clock/clock_nxt.c

@@ -98,10 +98,6 @@ void nx_systick_wait_ms(uint32_t ms) {
     }
 }
 
-void pbdrv_clock_busy_delay_ms(uint32_t ms) {
-    nx_systick_wait_ms(ms);
-}
-
 void nx_systick_wait_ns(uint32_t ns) {
     volatile uint32_t x = (ns >> 7) + 1;
 
@@ -110,9 +106,4 @@ void nx_systick_wait_ns(uint32_t ns) {
     }
 }
 
-bool pbdrv_clock_is_ticking(void) {
-    // TODO
-    return true;
-}
-
 #endif // PBDRV_CONFIG_CLOCK_NXT

lib/pbio/drv/clock/clock_stm32.c

@@ -92,6 +92,8 @@ uint32_t HAL_GetTick(void) {
 // We provide our own version of HAL_Delay that calls __WFI while waiting,
 // and works when interrupts are disabled.  This function is intended to be
 // used only by the ST HAL functions.
+//
+// TODO: Is anything actually still calling this?
 void HAL_Delay(uint32_t Delay) {
     if (__get_PRIMASK() == 0) {
         // IRQs enabled, so can use systick counter to do the delay
@@ -112,14 +114,4 @@ void HAL_Delay(uint32_t Delay) {
     }
 }
 
-void pbdrv_clock_busy_delay_ms(uint32_t ms) {
-    HAL_Delay(ms);
-}
-
-bool pbdrv_clock_is_ticking(void) {
-    // Init already completed in SystemInit(), so we just need to check if
-    // interrupts are enabled.
-    return __get_PRIMASK() == 0;
-}
-
 #endif // PBDRV_CONFIG_CLOCK_STM32

lib/pbio/drv/clock/clock_test.c

@@ -41,12 +41,5 @@ uint32_t pbdrv_clock_get_us(void) {
     return clock_ticks * 1000;
 }
 
-void pbdrv_clock_busy_delay_ms(uint32_t ms) {
-}
-
-bool pbdrv_clock_is_ticking(void) {
-    return true;
-}
-
 
 #endif // PBDRV_CONFIG_CLOCK_TEST

lib/pbio/include/pbdrv/clock.h

@@ -37,26 +37,6 @@ uint32_t pbdrv_clock_get_us(void);
  */
 void pbdrv_clock_busy_delay_us(uint32_t us);
 
-/**
- * Busy wait delay for several milliseconds. May not be accurate.
- *
- * NB: Should not be used in any driver code. This exists only as a hook for
- * APIs that need a blocking delay to work when interrupts could be disabled.
- *
- * @param [in]  ms  The number of milliseconds to delay.
- */
-void pbdrv_clock_busy_delay_ms(uint32_t ms);
-
-/**
- * Tests if the millisecond clock is ticking.
- *
- * On embedded systems, this means that the clock was initialized and IRQs are
- * enabled.
- *
- * @return True if the clock is ticking, false otherwise.
- */
-bool pbdrv_clock_is_ticking(void);
-
 #endif /* _PBDRV_CLOCK_H_ */
 
 /** @} */