From: Timo Wischer twischer@de.adit-jv.com

sometimes pulseaudio stops with the following assertion in libasound.so: alsa-lib-1.0.29/src/pcm/pcm.c:2761: snd_pcm_area_copy: Assertion `dst < src || dst >= src + bytes' failed. Application pointer is handled properly, in cases of rewind operations.

Signed-off-by: Timo Wischer twischer@de.adit-jv.com Signed-off-by: Ravikiran Polepalli ravikiran_polepalli@mentor.com Signed-off-by: Mikhail Durnev mikhail_durnev@mentor.com Signed-off-by: Mounesh Sutar sutar.mounesh@gmail.com

diff --git a/src/pcm/pcm_dmix.c b/src/pcm/pcm_dmix.c index dd0356e..4b763e2 100644 --- a/src/pcm/pcm_dmix.c +++ b/src/pcm/pcm_dmix.c @@ -706,7 +706,7 @@ static snd_pcm_sframes_t snd_pcm_dmix_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t f { snd_pcm_direct_t *dmix = pcm->private_data; snd_pcm_uframes_t slave_appl_ptr, slave_size; - snd_pcm_uframes_t appl_ptr, size, transfer, result; + snd_pcm_uframes_t appl_ptr, size, transfer, result, frames_to_remix; int err; const snd_pcm_channel_area_t *src_areas, *dst_areas;

@@ -717,6 +717,11 @@ static snd_pcm_sframes_t snd_pcm_dmix_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t f return err; }

+ /* (appl_ptr - last_appl_ptr) indicates the frames which are not already mixed + (last_appl_ptr - hw_ptr) indicates the frames which are already mixed but not played yet. + So they can be remixed. + */ + if (dmix->last_appl_ptr < dmix->appl_ptr) size = dmix->appl_ptr - dmix->last_appl_ptr; else @@ -729,6 +734,9 @@ static snd_pcm_sframes_t snd_pcm_dmix_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t f return size; result = size;

+ /* Always at this point last_appl_ptr == appl_ptr + So (appl_ptr - hw_ptr) indicates the frames which can be remixed + */ if (dmix->hw_ptr < dmix->appl_ptr) size = dmix->appl_ptr - dmix->hw_ptr; else @@ -741,9 +749,12 @@ static snd_pcm_sframes_t snd_pcm_dmix_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t f slave_size = dmix->slave_appl_ptr + (pcm->boundary - dmix->slave_hw_ptr); if (slave_size < size) size = slave_size; - frames -= size; - result += size; - + + /* frames which should be remixed will be saved + to also backward the appl pointer on success + */ + frames_to_remix = size; + /* add sample areas here */ src_areas = snd_pcm_mmap_areas(pcm); dst_areas = snd_pcm_mmap_areas(dmix->spcm); @@ -769,15 +780,15 @@ static snd_pcm_sframes_t snd_pcm_dmix_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t f appl_ptr += transfer; appl_ptr %= pcm->buffer_size; } - dmix->last_appl_ptr -= frames; - dmix->last_appl_ptr %= pcm->boundary; - dmix->slave_appl_ptr -= frames; - dmix->slave_appl_ptr %= dmix->slave_boundary; dmix_up_sem(dmix);

- snd_pcm_mmap_appl_backward(pcm, frames); + snd_pcm_mmap_appl_backward(pcm, frames_to_remix); + result += frames_to_remix; + /* At this point last_appl_ptr and appl_ptr has to indicate the + * position of the first not mixed frame + */

- return result + frames; + return result; }

static snd_pcm_sframes_t snd_pcm_dmix_forwardable(snd_pcm_t *pcm)