diff --git a/libraries/AP_HAL_ChibiOS/RCOutput.cpp b/libraries/AP_HAL_ChibiOS/RCOutput.cpp
index 1163b903eab2a..223e5844d873f 100644
--- a/libraries/AP_HAL_ChibiOS/RCOutput.cpp
+++ b/libraries/AP_HAL_ChibiOS/RCOutput.cpp
@@ -1071,6 +1071,7 @@ void RCOutput::set_group_mode(pwm_group &group)
 #if HAL_SERIALLED_ENABLED
     {
         uint8_t bits_per_pixel = 24;
+        uint32_t bit_width = NEOP_BIT_WIDTH_TICKS;
         bool active_high = true;
 
         if (!start_led_thread()) {
@@ -1080,6 +1081,7 @@ void RCOutput::set_group_mode(pwm_group &group)
 
         if (group.current_mode == MODE_PROFILED) {
             bits_per_pixel = 25;
+            bit_width = PROFI_BIT_WIDTH_TICKS;
             active_high = false;
         }
 
@@ -1094,7 +1096,7 @@ void RCOutput::set_group_mode(pwm_group &group)
         // calculate min time between pulses taking into account the DMAR parallelism
         const uint32_t pulse_time_us = 1000000UL * bit_length / rate;
 
-        if (!setup_group_DMA(group, rate, NEOP_BIT_WIDTH_TICKS, active_high, buffer_length, pulse_time_us, false)) {
+        if (!setup_group_DMA(group, rate, bit_width, active_high, buffer_length, pulse_time_us, false)) {
             group.current_mode = MODE_PWM_NONE;
             break;
         }
@@ -1698,7 +1700,8 @@ bool RCOutput::serial_led_send(pwm_group &group)
     }
 
 #if HAL_DSHOT_ENABLED
-    if (soft_serial_waiting() || (group.dshot_state != DshotState::IDLE && group.dshot_state != DshotState::RECV_COMPLETE)) {
+    if (soft_serial_waiting() || (group.dshot_state != DshotState::IDLE && group.dshot_state != DshotState::RECV_COMPLETE)
+        || AP_HAL::micros64() - group.last_dmar_send_us < (group.dshot_pulse_time_us + 50)) {
         // doing serial output or DMAR input, don't send DShot pulses
         return false;
     }
diff --git a/libraries/AP_HAL_ChibiOS/RCOutput.h b/libraries/AP_HAL_ChibiOS/RCOutput.h
index 5dd9e84643f7c..b0984b3bfdd8f 100644
--- a/libraries/AP_HAL_ChibiOS/RCOutput.h
+++ b/libraries/AP_HAL_ChibiOS/RCOutput.h
@@ -414,7 +414,7 @@ class ChibiOS::RCOutput : public AP_HAL::RCOutput
 #endif // HAL_WITH_BIDIR_DSHOT
         // are we safe to send another pulse?
         bool can_send_dshot_pulse() const {
-          return is_dshot_protocol(current_mode) && AP_HAL::micros() - last_dmar_send_us > (dshot_pulse_time_us + 50);
+          return is_dshot_protocol(current_mode) && AP_HAL::micros64() - last_dmar_send_us > (dshot_pulse_time_us + 50);
         }
 
         // return whether the group channel is both enabled in the group and for output