altos: Add ao_task_minimize_latency to reduce IRQ delays

[fw/altos] / src / core / ao_task.c

diff --git a/src/core/ao_task.c b/src/core/ao_task.c
index 0411fbdd425921c42f26b68d5116f932bfc18d96..9cb074b5220a2c6279353d1b4ab5371be2dd5385 100644 (file)
--- a/src/core/ao_task.c
+++ b/src/core/ao_task.c
@@ -305,6 +305,8 @@ ao_add_task(__xdata struct ao_task * task, void (*start)(void), __code char *nam
                );
 }
 
+__data uint8_t ao_task_minimize_latency;
+
 /* Task switching function. This must not use any stack variables */
 void
 ao_yield(void) ao_arch_naked_define
@@ -331,7 +333,12 @@ ao_yield(void) ao_arch_naked_define
        }
 
        ao_arch_isr_stack();
-       ao_arch_block_interrupts();
+#if !HAS_TASK_QUEUE
+       if (ao_task_minimize_latency)
+               ao_arch_release_interrupts();
+       else
+#endif
+               ao_arch_block_interrupts();
 
 #if AO_CHECK_STACK
        in_yield = 1;
@@ -374,7 +381,7 @@ ao_yield(void) ao_arch_naked_define
                                break;
 
                        /* Wait for interrupts when there's nothing ready */
-                       if (ao_cur_task_index == ao_last_task_index)
+                       if (ao_cur_task_index == ao_last_task_index && !ao_task_minimize_latency)
                                ao_arch_wait_interrupt();
                }
        }