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authorEliot Blennerhassett <eblennerhassett@audioscience.com>2011-03-25 15:25:47 +1300
committerTakashi Iwai <tiwai@suse.de>2011-03-25 12:42:45 +0100
commit26aebef420f8036213419b8a46e3a07db51439cd (patch)
treefa15570ca88e3deb8d05454f5cd2066a49337e1d /sound
parent7bf76c33e9a1ecb2a15f1a066d4e032b5d0922a7 (diff)
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.c21
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));

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