From: Andreas Pape apape@de.adit-jv.com
To avoid the chances of timeout, we need to check the enter poll in state xrun.
Signed-off-by: Andreas Pape apape@de.adit-jv.com
diff --git a/src/pcm/pcm_direct.c b/src/pcm/pcm_direct.c index 779845c..2928512 100644 --- a/src/pcm/pcm_direct.c +++ b/src/pcm/pcm_direct.c @@ -549,6 +549,42 @@ int snd_pcm_direct_timer_stop(snd_pcm_direct_t *dmix) snd_timer_stop(dmix->timer); return 0; } +/* + * This is the only operation guaranteed to be called before entering poll(). + * Direct plugins use fd of snd_timer to poll on, these timers do NOT check state of substream in kernel by intention. + * Only the enter to xrun might be notified once (SND_TIMER_EVENT_MSTOP). + * If xrun event was not correctly handled or was ignored it will never be evaluated again afterwards. + * This will result in snd_pcm_wait() always returning timeout. + * In contrast poll() on pcm hardware checks ALSA state and will immediately return POLLERR on XRUN. + * + * To prevent timeout and applications endlessly spinning without xrun detected we add a state check + * here which may trigger the xrun sequence. + * + * return count of filled descriptors or negative error code + */ +int snd_pcm_direct_poll_descriptors(snd_pcm_t *pcm, struct pollfd *pfds, unsigned int space) +{ + if (pcm->poll_fd < 0) { + SNDMSG("poll_fd < 0"); + return -EIO; + } + if (space >= 1 && pfds) { + pfds->fd = pcm->poll_fd; + pfds->events = pcm->poll_events | POLLERR | POLLNVAL; + } else { + return 0; + } + + /*this will also evaluate slave state and enter xrun if necessary*/ + switch (snd_pcm_state(pcm)) { + case SND_PCM_STATE_XRUN: + return -EPIPE; + default: + break; + } + return 1; +} +
int snd_pcm_direct_poll_revents(snd_pcm_t *pcm, struct pollfd *pfds, unsigned int nfds, unsigned short *revents) { diff --git a/src/pcm/pcm_direct.h b/src/pcm/pcm_direct.h index 569d2be..3a1c1c0 100644 --- a/src/pcm/pcm_direct.h +++ b/src/pcm/pcm_direct.h @@ -301,6 +301,7 @@ int snd_pcm_direct_parse_bindings(snd_pcm_direct_t *dmix, snd_config_t *cfg); int snd_pcm_direct_nonblock(snd_pcm_t *pcm, int nonblock); int snd_pcm_direct_async(snd_pcm_t *pcm, int sig, pid_t pid); +int snd_pcm_direct_poll_descriptors(snd_pcm_t *pcm, struct pollfd *pfds, unsigned int space); int snd_pcm_direct_poll_revents(snd_pcm_t *pcm, struct pollfd *pfds, unsigned int nfds, unsigned short *revents); int snd_pcm_direct_info(snd_pcm_t *pcm, snd_pcm_info_t * info); int snd_pcm_direct_hw_refine(snd_pcm_t *pcm, snd_pcm_hw_params_t *params); diff --git a/src/pcm/pcm_dmix.c b/src/pcm/pcm_dmix.c index 5c3eb2d..320c948 100644 --- a/src/pcm/pcm_dmix.c +++ b/src/pcm/pcm_dmix.c @@ -463,17 +463,23 @@ static int snd_pcm_dmix_sync_ptr(snd_pcm_t *pcm) static snd_pcm_state_t snd_pcm_dmix_state(snd_pcm_t *pcm) { snd_pcm_direct_t *dmix = pcm->private_data; + int err; snd_pcm_state_t state; state = snd_pcm_state(dmix->spcm); switch (state) { - case SND_PCM_STATE_XRUN: case SND_PCM_STATE_SUSPENDED: case SND_PCM_STATE_DISCONNECTED: dmix->state = state; return state; + case SND_PCM_STATE_XRUN: + if ((err = snd_pcm_direct_slave_recover(dmix)) < 0) + return err; + break; default: break; } + snd_pcm_direct_client_chk_xrun(dmix, pcm); + if (dmix->state == STATE_RUN_PENDING) return SNDRV_PCM_STATE_RUNNING; return dmix->state; @@ -969,7 +975,7 @@ static const snd_pcm_fast_ops_t snd_pcm_dmix_fast_ops = { .avail_update = snd_pcm_dmix_avail_update, .mmap_commit = snd_pcm_dmix_mmap_commit, .htimestamp = snd_pcm_dmix_htimestamp, - .poll_descriptors = NULL, + .poll_descriptors = snd_pcm_direct_poll_descriptors, .poll_descriptors_count = NULL, .poll_revents = snd_pcm_dmix_poll_revents, }; diff --git a/src/pcm/pcm_dshare.c b/src/pcm/pcm_dshare.c index 707e2c2..f4fa32b 100644 --- a/src/pcm/pcm_dshare.c +++ b/src/pcm/pcm_dshare.c @@ -255,17 +255,22 @@ static int snd_pcm_dshare_status(snd_pcm_t *pcm, snd_pcm_status_t * status) static snd_pcm_state_t snd_pcm_dshare_state(snd_pcm_t *pcm) { snd_pcm_direct_t *dshare = pcm->private_data; + int err; snd_pcm_state_t state; state = snd_pcm_state(dshare->spcm); switch (state) { - case SND_PCM_STATE_XRUN: case SND_PCM_STATE_SUSPENDED: case SND_PCM_STATE_DISCONNECTED: dshare->state = state; return state; + case SND_PCM_STATE_XRUN: + if ((err = snd_pcm_direct_slave_recover(dshare)) < 0) + return err; + break; default: break; } + snd_pcm_direct_client_chk_xrun(dshare, pcm); if (dshare->state == STATE_RUN_PENDING) return SNDRV_PCM_STATE_RUNNING; return dshare->state; @@ -646,7 +651,7 @@ static const snd_pcm_fast_ops_t snd_pcm_dshare_fast_ops = { .avail_update = snd_pcm_dshare_avail_update, .mmap_commit = snd_pcm_dshare_mmap_commit, .htimestamp = snd_pcm_dshare_htimestamp, - .poll_descriptors = NULL, + .poll_descriptors = snd_pcm_direct_poll_descriptors, .poll_descriptors_count = NULL, .poll_revents = snd_pcm_direct_poll_revents, }; diff --git a/src/pcm/pcm_dsnoop.c b/src/pcm/pcm_dsnoop.c index 512e957..0729a5a 100644 --- a/src/pcm/pcm_dsnoop.c +++ b/src/pcm/pcm_dsnoop.c @@ -208,17 +208,22 @@ static int snd_pcm_dsnoop_status(snd_pcm_t *pcm, snd_pcm_status_t * status) static snd_pcm_state_t snd_pcm_dsnoop_state(snd_pcm_t *pcm) { snd_pcm_direct_t *dsnoop = pcm->private_data; + int err; snd_pcm_state_t state; state = snd_pcm_state(dsnoop->spcm); switch (state) { - case SND_PCM_STATE_XRUN: case SND_PCM_STATE_SUSPENDED: case SND_PCM_STATE_DISCONNECTED: dsnoop->state = state; return state; + case SND_PCM_STATE_XRUN: + if ((err = snd_pcm_direct_slave_recover(dsnoop)) < 0) + return err; + break; default: break; } + snd_pcm_direct_client_chk_xrun(dsnoop, pcm); return dsnoop->state; }
@@ -531,7 +536,7 @@ static const snd_pcm_fast_ops_t snd_pcm_dsnoop_fast_ops = { .avail_update = snd_pcm_dsnoop_avail_update, .mmap_commit = snd_pcm_dsnoop_mmap_commit, .htimestamp = snd_pcm_dsnoop_htimestamp, - .poll_descriptors = NULL, + .poll_descriptors = snd_pcm_direct_poll_descriptors, .poll_descriptors_count = NULL, .poll_revents = snd_pcm_direct_poll_revents, };