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-rw-r--r--sound/pci/cmipci.c68
1 files changed, 67 insertions, 1 deletions
diff --git a/sound/pci/cmipci.c b/sound/pci/cmipci.c
index 085a36751ac0..6832649879ce 100644
--- a/sound/pci/cmipci.c
+++ b/sound/pci/cmipci.c
@@ -434,6 +434,7 @@ struct cmipci_pcm {
u8 running; /* dac/adc running? */
u8 fmt; /* format bits */
u8 is_dac;
+ u8 needs_silencing;
unsigned int dma_size; /* in frames */
unsigned int shift;
unsigned int ch; /* channel (0/1) */
@@ -903,6 +904,7 @@ static int snd_cmipci_pcm_trigger(struct cmipci *cm, struct cmipci_pcm *rec,
cm->ctrl &= ~chen;
snd_cmipci_write(cm, CM_REG_FUNCTRL0, cm->ctrl | reset);
snd_cmipci_write(cm, CM_REG_FUNCTRL0, cm->ctrl & ~reset);
+ rec->needs_silencing = rec->is_dac;
break;
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
case SNDRV_PCM_TRIGGER_SUSPEND:
@@ -1304,11 +1306,75 @@ static int snd_cmipci_playback_spdif_prepare(struct snd_pcm_substream *substream
return snd_cmipci_pcm_prepare(cm, &cm->channel[CM_CH_PLAY], substream);
}
+/*
+ * Apparently, the samples last played on channel A stay in some buffer, even
+ * after the channel is reset, and get added to the data for the rear DACs when
+ * playing a multichannel stream on channel B. This is likely to generate
+ * wraparounds and thus distortions.
+ * To avoid this, we play at least one zero sample after the actual stream has
+ * stopped.
+ */
+static void snd_cmipci_silence_hack(struct cmipci *cm, struct cmipci_pcm *rec)
+{
+ struct snd_pcm_runtime *runtime = rec->substream->runtime;
+ unsigned int reg, val;
+
+ if (rec->needs_silencing && runtime && runtime->dma_area) {
+ /* set up a small silence buffer */
+ memset(runtime->dma_area, 0, PAGE_SIZE);
+ reg = rec->ch ? CM_REG_CH1_FRAME2 : CM_REG_CH0_FRAME2;
+ val = ((PAGE_SIZE / 4) - 1) | (((PAGE_SIZE / 4) / 2 - 1) << 16);
+ snd_cmipci_write(cm, reg, val);
+
+ /* configure for 16 bits, 2 channels, 8 kHz */
+ if (runtime->channels > 2)
+ set_dac_channels(cm, rec, 2);
+ spin_lock_irq(&cm->reg_lock);
+ val = snd_cmipci_read(cm, CM_REG_FUNCTRL1);
+ val &= ~(CM_ASFC_MASK << (rec->ch * 3));
+ val |= (4 << CM_ASFC_SHIFT) << (rec->ch * 3);
+ snd_cmipci_write(cm, CM_REG_FUNCTRL1, val);
+ val = snd_cmipci_read(cm, CM_REG_CHFORMAT);
+ val &= ~(CM_CH0FMT_MASK << (rec->ch * 2));
+ val |= (3 << CM_CH0FMT_SHIFT) << (rec->ch * 2);
+ if (cm->chip_version == 68) {
+ val &= ~(CM_CH0_SRATE_88K << (rec->ch * 2));
+ val &= ~(CM_CH0_SRATE_96K << (rec->ch * 2));
+ }
+ snd_cmipci_write(cm, CM_REG_CHFORMAT, val);
+
+ /* start stream (we don't need interrupts) */
+ cm->ctrl |= CM_CHEN0 << rec->ch;
+ snd_cmipci_write(cm, CM_REG_FUNCTRL0, cm->ctrl);
+ spin_unlock_irq(&cm->reg_lock);
+
+ msleep(1);
+
+ /* stop and reset stream */
+ spin_lock_irq(&cm->reg_lock);
+ cm->ctrl &= ~(CM_CHEN0 << rec->ch);
+ val = CM_RST_CH0 << rec->ch;
+ snd_cmipci_write(cm, CM_REG_FUNCTRL0, cm->ctrl | val);
+ snd_cmipci_write(cm, CM_REG_FUNCTRL0, cm->ctrl & ~val);
+ spin_unlock_irq(&cm->reg_lock);
+
+ rec->needs_silencing = 0;
+ }
+}
+
static int snd_cmipci_playback_hw_free(struct snd_pcm_substream *substream)
{
struct cmipci *cm = snd_pcm_substream_chip(substream);
setup_spdif_playback(cm, substream, 0, 0);
restore_mixer_state(cm);
+ snd_cmipci_silence_hack(cm, &cm->channel[0]);
+ return snd_cmipci_hw_free(substream);
+}
+
+static int snd_cmipci_playback2_hw_free(struct snd_pcm_substream *substream)
+{
+ struct cmipci *cm = snd_pcm_substream_chip(substream);
+ snd_cmipci_silence_hack(cm, &cm->channel[1]);
return snd_cmipci_hw_free(substream);
}
@@ -1736,7 +1802,7 @@ static struct snd_pcm_ops snd_cmipci_playback2_ops = {
.close = snd_cmipci_playback2_close,
.ioctl = snd_pcm_lib_ioctl,
.hw_params = snd_cmipci_playback2_hw_params,
- .hw_free = snd_cmipci_hw_free,
+ .hw_free = snd_cmipci_playback2_hw_free,
.prepare = snd_cmipci_capture_prepare, /* channel B */
.trigger = snd_cmipci_capture_trigger, /* channel B */
.pointer = snd_cmipci_capture_pointer, /* channel B */