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Fix mmap with multi plugin

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The mmap of multi plugin seems broken (for a long time!) due to its
creation of local buffer via snd_pcm_mmap().  Since the multi plugin
just needs to shadow the mmap buffer of each slave, it now has
mmap_shadow=1 and its own mmap/unmap method to do shadowing.
This commit is contained in:
Takashi Iwai 2007-11-23 15:46:48 +01:00
parent 683c8bc4a2
commit 0b66de95a9
1 changed files with 34 additions and 2 deletions
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36
src/pcm/pcm_multi.c
View file

@ -690,13 +690,44 @@ static snd_pcm_sframes_t snd_pcm_multi_mmap_commit(snd_pcm_t *pcm,
return size; return size;
} }
static int snd_pcm_multi_mmap(snd_pcm_t *pcm ATTRIBUTE_UNUSED) static int snd_pcm_multi_munmap(snd_pcm_t *pcm)
{ {
free(pcm->mmap_channels);
free(pcm->running_areas);
pcm->mmap_channels = NULL;
pcm->running_areas = NULL;
return 0; return 0;
} }
static int snd_pcm_multi_munmap(snd_pcm_t *pcm ATTRIBUTE_UNUSED) static int snd_pcm_multi_mmap(snd_pcm_t *pcm)
{ {
snd_pcm_multi_t *multi = pcm->private_data;
unsigned int c;
pcm->mmap_channels = calloc(pcm->channels,
sizeof(pcm->mmap_channels[0]));
pcm->running_areas = calloc(pcm->channels,
sizeof(pcm->running_areas[0]));
if (!pcm->mmap_channels || !pcm->running_areas) {
snd_pcm_multi_munmap(pcm);
return -ENOMEM;
}
/* Copy the slave mmapped buffer data */
for (c = 0; c < pcm->channels; c++) {
snd_pcm_multi_channel_t *chan = &multi->channels[c];
snd_pcm_t *slave;
if (chan->slave_idx < 0) {
snd_pcm_multi_munmap(pcm);
return -ENXIO;
}
slave = multi->slaves[chan->slave_idx].pcm;
pcm->mmap_channels[c] =
slave->mmap_channels[chan->slave_channel];
pcm->mmap_channels[c].channel = c;
pcm->running_areas[c] =
slave->running_areas[chan->slave_channel];
}
return 0; return 0;
} }
@ -850,6 +881,7 @@ int snd_pcm_multi_open(snd_pcm_t **pcmp, const char *name,
return err; return err;
} }
pcm->mmap_rw = 1; pcm->mmap_rw = 1;
pcm->mmap_shadow = 1; /* has own mmap method */
pcm->ops = &snd_pcm_multi_ops; pcm->ops = &snd_pcm_multi_ops;
pcm->fast_ops = &snd_pcm_multi_fast_ops; pcm->fast_ops = &snd_pcm_multi_fast_ops;
pcm->private_data = multi; pcm->private_data = multi;