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| author | Takashi Sakamoto <o-takashi@sakamocchi.jp> | 2014-08-29 04:40:45 (GMT) |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2014-08-29 07:52:07 (GMT) |
| commit | 65845f29bec6bc17f80eff25c3bc39bcf3be9bf9 (patch) | |
| tree | 5fd70c1a8a22e4c439887020f2a3ef7df1673361 /sound/firewire/amdtp.c | |
| parent | 1033eb5b5aeeb526c22068e0fb0cef9f3c14231e (diff) | |
| download | linux-65845f29bec6bc17f80eff25c3bc39bcf3be9bf9.tar.xz | |
ALSA: firewire-lib/dice: add arrangements of PCM pointer and interrupts for Dice quirk
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 10550bea44a8 ("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: 10550bea44a8 ("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>
Diffstat (limited to 'sound/firewire/amdtp.c')
| -rw-r--r-- | sound/firewire/amdtp.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/sound/firewire/amdtp.c b/sound/firewire/amdtp.c index f96bf4c..95fc2eaf 100644 --- a/sound/firewire/amdtp.c +++ b/sound/firewire/amdtp.c @@ -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) |