From 77bc1ba03e75bb772d6fb0ce7096d870d95f1ad0 Mon Sep 17 00:00:00 2001 From: Jeff Epler Date: Sat, 3 Aug 2019 08:19:25 -0500 Subject: nrf: PWMAudioOut: Remove the need to wait in "pause" The original formulation was because I saw the need to avoid a transition from playing to stopped exactly when a resume was taking place. However, @tannewt was concerned about this pause causing trouble, because it could be relatively lengthy (several ms even in a typical case). After reflection, I've convinced myself that updating the registers in this order in resume avoids a window where a "stopped" event can be missed as long as the shortcut is updated first. Testing re-performed: pause/resume testing of looped RawSample and WaveFile audio sources. --- ports/nrf/common-hal/audiopwmio/PWMAudioOut.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/ports/nrf/common-hal/audiopwmio/PWMAudioOut.c b/ports/nrf/common-hal/audiopwmio/PWMAudioOut.c index 6e22df7c3..0321b751c 100644 --- a/ports/nrf/common-hal/audiopwmio/PWMAudioOut.c +++ b/ports/nrf/common-hal/audiopwmio/PWMAudioOut.c @@ -295,19 +295,20 @@ bool common_hal_audiopwmio_pwmaudioout_get_playing(audiopwmio_pwmaudioout_obj_t* * Perhaps the way forward is to divide even "single buffer" samples into tasks of * only a few ms long, so that they can be stopped/restarted quickly enough that it * feels instant. (This also saves on memory, for long in-memory "single buffer" - * samples!) + * samples, since we have to locally take a resampled copy!) */ void common_hal_audiopwmio_pwmaudioout_pause(audiopwmio_pwmaudioout_obj_t* self) { self->paused = true; self->pwm->SHORTS = NRF_PWM_SHORT_SEQEND1_STOP_MASK; - while(!self->pwm->EVENTS_STOPPED) { /* NOTHING */ } } void common_hal_audiopwmio_pwmaudioout_resume(audiopwmio_pwmaudioout_obj_t* self) { self->paused = false; self->pwm->SHORTS = NRF_PWM_SHORT_LOOPSDONE_SEQSTART0_MASK; - self->pwm->EVENTS_STOPPED = 0; - self->pwm->TASKS_SEQSTART[0] = 1; + if (self->pwm->EVENTS_STOPPED) { + self->pwm->EVENTS_STOPPED = 0; + self->pwm->TASKS_SEQSTART[0] = 1; + } } bool common_hal_audiopwmio_pwmaudioout_get_paused(audiopwmio_pwmaudioout_obj_t* self) { -- cgit v1.2.3