From 5980f6988a49fe101292fa1bd43315be795a135c Mon Sep 17 00:00:00 2001 From: Wim Taymans Date: Tue, 12 Dec 2023 10:06:46 +0100 Subject: [PATCH] Revert "alsa: also use interpolated time as nsec in IRQ mode" This reverts commit 49cdb468c28ba366dbd08eef9cb6dbf2dea2a2e5. We should not do this, the nsec field should be relatable to the clock monotonic time. If we use the estimated time, without actually using it as a timer, we might end up with a wakeup time in the future compared to the MONOTONIC clock time. Instead, you can use the estimated current time simply by subtracting the rate corrected duration from the next_nsec. This is really only useful for some selected use cases (like in the JACK library). This fixes some issues where in pro-audio mode, a client would try to compare the current MONOTONIC time to nsec and find that it is in the past. This commit was done in an attempt to fix #3657 but it turned out the real problem was something else. --- spa/plugins/alsa/alsa-pcm.c | 32 +++++++++++++------------------- 1 file changed, 13 insertions(+), 19 deletions(-) diff --git a/spa/plugins/alsa/alsa-pcm.c b/spa/plugins/alsa/alsa-pcm.c index a636472ec..d59539f8a 100644 --- a/spa/plugins/alsa/alsa-pcm.c +++ b/spa/plugins/alsa/alsa-pcm.c @@ -2532,15 +2532,6 @@ static int get_status(struct state *state, uint64_t current_time, snd_pcm_uframe return 0; } - -static uint64_t get_time_ns(struct state *state) -{ - struct timespec now; - if (spa_system_clock_gettime(state->data_system, CLOCK_MONOTONIC, &now) < 0) - return 0; - return SPA_TIMESPEC_TO_NSEC(&now); -} - static int update_time(struct state *state, uint64_t current_time, snd_pcm_sframes_t delay, snd_pcm_sframes_t target, bool follower) { @@ -2548,15 +2539,8 @@ static int update_time(struct state *state, uint64_t current_time, snd_pcm_sfram int32_t diff; if (state->disable_tsched && !follower) { - uint64_t now = get_time_ns(state); - - if (SPA_UNLIKELY(state->dll.bw == 0.0)) { - current_time = now; - err = 0.0; - } else { - err = (int64_t)(now - current_time); - err = err / 1e9 * state->rate; - } + err = (int64_t)(current_time - state->next_time); + err = err / 1e9 * state->rate; } else { if (state->stream == SND_PCM_STREAM_PLAYBACK) err = delay - target; @@ -3183,6 +3167,14 @@ static int capture_ready(struct state *state) return 0; } +static uint64_t get_time_ns(struct state *state) +{ + struct timespec now; + if (spa_system_clock_gettime(state->data_system, CLOCK_MONOTONIC, &now) < 0) + return 0; + return SPA_TIMESPEC_TO_NSEC(&now); +} + static void alsa_wakeup_event(struct spa_source *source) { struct state *state = source->data, *follower; @@ -3194,6 +3186,8 @@ static void alsa_wakeup_event(struct spa_source *source) int err; unsigned short revents; + current_time = get_time_ns(state); + for (int i = 0; i < state->n_fds; i++) { state->pfds[i].revents = state->source[i].rmask; /* Reset so that we only handle all our sources' events once */ @@ -3229,8 +3223,8 @@ static void alsa_wakeup_event(struct spa_source *source) return; } } + current_time = state->next_time; } - current_time = state->next_time; /* first do all the sync */ if (state->stream == SND_PCM_STREAM_CAPTURE)