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ALSA: firewire-lib/dice: add arrangements of PCM pointer and interrupts for Dice quirk

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In IEC 61883-6, one data block transfers one event. In ALSA, the event equals one PCM frame,
hence one data block transfers one PCM frame. But Dice has a quirk at higher sampling rate
(176.4/192.0 kHz) that one data block transfers two PCM frames.

Commit 10550bea44 ("ALSA: dice/firewire-lib: Keep dualwire mode but obsolete
CIP_HI_DUALWIRE") moved some codes related to this quirk into Dice driver. But the commit
forgot to add arrangements for PCM period interrupts and DMA pointer updates. As a result, Dice
driver cannot work correctly at higher sampling rate.

This commit adds 'double_pcm_frames' parameter to amdtp structure for this quirk. When this
parameter is set, PCM period interrupts and DMA pointer updates occur at double speed than in
IEC 61883-6.

Reported-by: Daniel Robbins <drobbins@funtoo.org>
Fixes: 10550bea44 ("ALSA: dice/firewire-lib: Keep dualwire mode but obsolete CIP_HI_DUALWIRE")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Cc: <stable@vger.kernel.org> # 3.16
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Sakamoto
2014-08-29 13:40:45 +09:00
committed by Takashi Iwai
parent 1033eb5b5a
commit 65845f29be
3 changed files with 22 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
sound/firewire/amdtp.c
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@@ -507,7 +507,16 @@ static void amdtp_pull_midi(struct amdtp_stream *s,
static void update_pcm_pointers(struct amdtp_stream *s,
struct snd_pcm_substream *pcm,
unsigned int frames)
{ unsigned int ptr;
{
unsigned int ptr;
/*
* In IEC 61883-6, one data block represents one event. In ALSA, one
* event equals to one PCM frame. But Dice has a quirk to transfer
* two PCM frames in one data block.
*/
if (s->double_pcm_frames)
frames *= 2;
ptr = s->pcm_buffer_pointer + frames;
if (ptr >= pcm->runtime->buffer_size)