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>
diff --git a/sound/pci/oxygen/oxygen_pcm.c b/sound/pci/oxygen/oxygen_pcm.c
index c262049..3b5ca70 100644
--- a/sound/pci/oxygen/oxygen_pcm.c
+++ b/sound/pci/oxygen/oxygen_pcm.c
@@ -487,10 +487,14 @@
{
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);