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Diffstat (limited to 'sound/usb/usbaudio.c')
-rw-r--r--sound/usb/usbaudio.c39
1 files changed, 38 insertions, 1 deletions
diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index a6b88482637b..c7b902358b7b 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -627,6 +627,7 @@ static int prepare_playback_urb(struct snd_usb_substream *subs,
subs->hwptr_done += offs;
if (subs->hwptr_done >= runtime->buffer_size)
subs->hwptr_done -= runtime->buffer_size;
+ runtime->delay += offs;
spin_unlock_irqrestore(&subs->lock, flags);
urb->transfer_buffer_length = offs * stride;
if (period_elapsed)
@@ -636,12 +637,22 @@ static int prepare_playback_urb(struct snd_usb_substream *subs,
/*
* process after playback data complete
- * - nothing to do
+ * - decrease the delay count again
*/
static int retire_playback_urb(struct snd_usb_substream *subs,
struct snd_pcm_runtime *runtime,
struct urb *urb)
{
+ unsigned long flags;
+ int stride = runtime->frame_bits >> 3;
+ int processed = urb->transfer_buffer_length / stride;
+
+ spin_lock_irqsave(&subs->lock, flags);
+ if (processed > runtime->delay)
+ runtime->delay = 0;
+ else
+ runtime->delay -= processed;
+ spin_unlock_irqrestore(&subs->lock, flags);
return 0;
}
@@ -1520,6 +1531,7 @@ static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
subs->hwptr_done = 0;
subs->transfer_done = 0;
subs->phase = 0;
+ runtime->delay = 0;
/* clear urbs (to be sure) */
deactivate_urbs(subs, 0, 1);
@@ -3279,6 +3291,25 @@ static int snd_usb_cm106_boot_quirk(struct usb_device *dev)
return snd_usb_cm106_write_int_reg(dev, 2, 0x8004);
}
+/*
+ * C-Media CM6206 is based on CM106 with two additional
+ * registers that are not documented in the data sheet.
+ * Values here are chosen based on sniffing USB traffic
+ * under Windows.
+ */
+static int snd_usb_cm6206_boot_quirk(struct usb_device *dev)
+{
+ int err, reg;
+ int val[] = {0x200c, 0x3000, 0xf800, 0x143f, 0x0000, 0x3000};
+
+ for (reg = 0; reg < ARRAY_SIZE(val); reg++) {
+ err = snd_usb_cm106_write_int_reg(dev, reg, val[reg]);
+ if (err < 0)
+ return err;
+ }
+
+ return err;
+}
/*
* Setup quirks
@@ -3565,6 +3596,12 @@ static void *snd_usb_audio_probe(struct usb_device *dev,
goto __err_val;
}
+ /* C-Media CM6206 / CM106-Like Sound Device */
+ if (id == USB_ID(0x0d8c, 0x0102)) {
+ if (snd_usb_cm6206_boot_quirk(dev) < 0)
+ goto __err_val;
+ }
+
/*
* found a config. now register to ALSA
*/