Record doesn't work if enabling mmap emulation and rate conversion needed, this patch fix this bug.

diff -uNr alsa-lib-1.0.14a/src/pcm/pcm_hw.c alsa-lib-new/src/pcm/pcm_hw.c --- alsa-lib-1.0.14a/src/pcm/pcm_hw.c 2007-06-11 16:53:13.000000000 +0800 +++ alsa-lib-new/src/pcm/pcm_hw.c 2007-07-04 12:16:31.000000000 +0800 @@ -96,6 +96,7 @@ int shadow_appl_ptr: 1, avail_update_flag: 1, mmap_shm: 1; + snd_pcm_uframes_t hw_ptr; snd_pcm_uframes_t appl_ptr; /* restricted parameters */ snd_pcm_format_t format; @@ -373,7 +374,9 @@ if (pcm->stream == SND_PCM_STREAM_CAPTURE) { if (hw->mmap_shm) { hw->shadow_appl_ptr = 1; + hw->hw_ptr = 0; hw->appl_ptr = 0; + snd_pcm_set_hw_ptr(pcm, &hw->hw_ptr, -1, 0); snd_pcm_set_appl_ptr(pcm, &hw->appl_ptr, -1, 0); } else { hw->shadow_appl_ptr = 0; @@ -949,28 +952,91 @@ return size; }

+static inline snd_pcm_uframes_t snd_pcm_hw_capture_avail(snd_pcm_t *pcm) +{ + snd_pcm_sframes_t avail; + snd_pcm_hw_t *hw = pcm->private_data; + + avail = hw->mmap_status->hw_ptr - hw->mmap_control->appl_ptr; + if (avail < 0) + avail += pcm->boundary; + return avail; +} + +static snd_pcm_sframes_t snd_pcm_hw_read_mmap(snd_pcm_t *pcm, snd_pcm_uframes_t size) +{ + snd_pcm_uframes_t xfer = 0; + snd_pcm_sframes_t err = 0; + snd_pcm_hw_t *hw = pcm->private_data; + if (! size) + return 0; + while (xfer < size) { + snd_pcm_uframes_t frames = size - xfer; + snd_pcm_uframes_t appl_offset = hw->mmap_control->appl_ptr % pcm->buffer_size; + snd_pcm_uframes_t cont = pcm->buffer_size - appl_offset; + if (cont < frames) + frames = cont; + switch (pcm->access) { + case SND_PCM_ACCESS_MMAP_INTERLEAVED: + { + const snd_pcm_channel_area_t *a = snd_pcm_mmap_areas(pcm); + char *buf = snd_pcm_channel_area_addr(a, appl_offset); + err = _snd_pcm_readi(pcm, buf, frames); + if (err >= 0) + frames = err; + break; + } + case SND_PCM_ACCESS_MMAP_NONINTERLEAVED: + { + snd_pcm_uframes_t channels = pcm->channels; + unsigned int c; + void *bufs[channels]; + const snd_pcm_channel_area_t *areas = snd_pcm_mmap_areas(pcm); + for (c = 0; c < channels; ++c) { + const snd_pcm_channel_area_t *a = &areas[c]; + bufs[c] = snd_pcm_channel_area_addr(a, appl_offset); + } + err = _snd_pcm_readn(pcm->fast_op_arg, bufs, frames); + if (err >= 0) + frames = err; + } + default: + SNDMSG("invalid access type %d", pcm->access); + return -EINVAL; + } + if (err < 0) + break; + xfer += frames; + } + if (xfer > 0) + return xfer; + return err; +} + static snd_pcm_sframes_t snd_pcm_hw_avail_update(snd_pcm_t *pcm) { snd_pcm_hw_t *hw = pcm->private_data; - snd_pcm_uframes_t avail; + snd_pcm_uframes_t avail, xfer_avail;

sync_ptr(hw, 0); if (pcm->stream == SND_PCM_STREAM_PLAYBACK) { avail = snd_pcm_mmap_playback_avail(pcm); } else { avail = snd_pcm_mmap_capture_avail(pcm); - if (avail > 0 && hw->mmap_shm) { + if (avail < pcm->avail_min && hw->mmap_shm) { snd_pcm_sframes_t err; - snd_pcm_hw_t *hw = pcm->private_data; - hw->avail_update_flag = 1; - err = snd_pcm_read_mmap(pcm, avail); - hw->avail_update_flag = 0; - if (err < 0) - return err; - if ((snd_pcm_uframes_t)err != avail) - SNDMSG("short read %ld for avail %ld", err, avail); - return err; - } + xfer_avail = snd_pcm_hw_capture_avail(pcm); + xfer_avail -= xfer_avail % pcm->xfer_align; + if (xfer_avail > 0) { + hw->avail_update_flag = 1; + err = snd_pcm_hw_read_mmap(pcm, xfer_avail); + hw->avail_update_flag = 0; + if (err < 0) + return err; + hw->hw_ptr += err; + avail = snd_pcm_mmap_capture_avail(pcm); + } + } } switch (FAST_PCM_STATE(hw)) { case SNDRV_PCM_STATE_RUNNING: