diff options
| author | Eliot Blennerhassett <eblennerhassett@audioscience.com> | 2011-03-25 03:25:47 +0100 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2011-03-25 12:42:45 +0100 |
| commit | 26aebef420f8036213419b8a46e3a07db51439cd (patch) | |
| tree | fa15570ca88e3deb8d05454f5cd2066a49337e1d /sound | |
| parent | ALSA: asihpi - Support single-rate no-SRC cards (diff) | |
| download | linux-26aebef420f8036213419b8a46e3a07db51439cd.tar.xz linux-26aebef420f8036213419b8a46e3a07db51439cd.zip | |
ALSA: asihpi - Improve non-busmaster adapter operation
Make playback silence callback a no-op, card automatically outputs
silence when written data runs out.
Increasing update interval and thus minimum period avoids xrun on startup
or because of timer jitter.
Signed-off-by: Eliot Blennerhassett <eblennerhassett@audioscience.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/pci/asihpi/asihpi.c | 21 |
1 files changed, 10 insertions, 11 deletions
diff --git a/sound/pci/asihpi/asihpi.c b/sound/pci/asihpi/asihpi.c index 22606e3b08f4..c90d77ad681b 100644 --- a/sound/pci/asihpi/asihpi.c +++ b/sound/pci/asihpi/asihpi.c @@ -1012,6 +1012,7 @@ static int snd_card_asihpi_playback_open(struct snd_pcm_substream *substream) snd_pcm_hw_constraint_step(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, card->update_interval_frames); + snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, card->update_interval_frames * 2, UINT_MAX); @@ -1054,7 +1055,7 @@ static int snd_card_asihpi_playback_copy(struct snd_pcm_substream *substream, hpi_handle_error(hpi_outstream_write_buf(dpcm->h_stream, runtime->dma_area, len, &dpcm->format)); - dpcm->pcm_buf_host_rw_ofs = dpcm->pcm_buf_host_rw_ofs + len; + dpcm->pcm_buf_host_rw_ofs += len; return 0; } @@ -1064,16 +1065,11 @@ static int snd_card_asihpi_playback_silence(struct snd_pcm_substream * snd_pcm_uframes_t pos, snd_pcm_uframes_t count) { - unsigned int len; - struct snd_pcm_runtime *runtime = substream->runtime; - struct snd_card_asihpi_pcm *dpcm = runtime->private_data; - - len = frames_to_bytes(runtime, count); - VPRINTK1(KERN_INFO "playback silence %u bytes\n", len); - - memset(runtime->dma_area, 0, len); - hpi_handle_error(hpi_outstream_write_buf(dpcm->h_stream, - runtime->dma_area, len, &dpcm->format)); + /* Usually writes silence to DMA buffer, which should be overwritten + by real audio later. Our fifos cannot be overwritten, and are not + free-running DMAs. Silence is output on fifo underflow. + This callback is still required to allow the copy callback to be used. + */ return 0; } @@ -2885,6 +2881,9 @@ static int __devinit snd_asihpi_probe(struct pci_dev *pci_dev, if (err) asihpi->update_interval_frames = 512; + if (!asihpi->support_mmap) + asihpi->update_interval_frames *= 2; + hpi_handle_error(hpi_instream_open(asihpi->adapter_index, 0, &h_stream)); |