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| author |   Clemens Ladisch <clemens@ladisch.de> | 2009-05-25 10:05:00 +0200 |
|---|---|---|
| committer |   Takashi Iwai <tiwai@suse.de> | 2009-05-25 11:49:30 +0200 |
| commit | 345c03ef0f2bd0c933a1eca27732af7edf5e8d4d (patch) | |
| tree | eb0e81e821910743a585cc34cb8b49e70b3da7ed /sound/pci/oxygen | |
| parent | Linux 2.6.30-rc7 (diff) | |
| download | linux-dev-345c03ef0f2bd0c933a1eca27732af7edf5e8d4d.tar.xz linux-dev-345c03ef0f2bd0c933a1eca27732af7edf5e8d4d.zip | |
sound: oxygen: reset DMA when stream is closed
When a PCM stream is closed, flush the corresponding DMA channel.
Otherwise, the DMA controller would continue to output the last sample
which would result in a DC offset on the output.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/pci/oxygen')
| -rw-r--r-- | sound/pci/oxygen/oxygen_pcm.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/sound/pci/oxygen/oxygen_pcm.c b/sound/pci/oxygen/oxygen_pcm.c index c262049961e1..3b5ca70c9d4d 100644 --- a/sound/pci/oxygen/oxygen_pcm.c +++ b/sound/pci/oxygen/oxygen_pcm.c @@ -487,10 +487,14 @@ static int oxygen_hw_free(struct snd_pcm_substream *substream) { struct oxygen *chip = snd_pcm_substream_chip(substream); unsigned int channel = oxygen_substream_channel(substream); + unsigned int channel_mask = 1 << channel; spin_lock_irq(&chip->reg_lock); - chip->interrupt_mask &= ~(1 << channel); + chip->interrupt_mask &= ~channel_mask; oxygen_write16(chip, OXYGEN_INTERRUPT_MASK, chip->interrupt_mask); + + oxygen_set_bits8(chip, OXYGEN_DMA_FLUSH, channel_mask); + oxygen_clear_bits8(chip, OXYGEN_DMA_FLUSH, channel_mask); spin_unlock_irq(&chip->reg_lock); return snd_pcm_lib_free_pages(substream); |