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author | Takashi Sakamoto <o-takashi@sakamocchi.jp> | 2014-08-29 08:40:45 +0400 |
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committer | Takashi Iwai <tiwai@suse.de> | 2014-08-29 11:52:07 +0400 |
commit | 65845f29bec6bc17f80eff25c3bc39bcf3be9bf9 (patch) | |
tree | 5fd70c1a8a22e4c439887020f2a3ef7df1673361 /sound | |
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')
-rw-r--r-- | sound/firewire/amdtp.c | 11 | ||||
-rw-r--r-- | sound/firewire/amdtp.h | 1 | ||||
-rw-r--r-- | sound/firewire/dice.c | 15 |
3 files changed, 22 insertions, 5 deletions
diff --git a/sound/firewire/amdtp.c b/sound/firewire/amdtp.c index f96bf4c7c232..95fc2eaf11dc 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) diff --git a/sound/firewire/amdtp.h b/sound/firewire/amdtp.h index d8ee7b0e9386..4823c08196ac 100644 --- a/sound/firewire/amdtp.h +++ b/sound/firewire/amdtp.h @@ -125,6 +125,7 @@ struct amdtp_stream { unsigned int pcm_buffer_pointer; unsigned int pcm_period_pointer; bool pointer_flush; + bool double_pcm_frames; struct snd_rawmidi_substream *midi[AMDTP_MAX_CHANNELS_FOR_MIDI * 8]; diff --git a/sound/firewire/dice.c b/sound/firewire/dice.c index 4cf8eb704045..e3a04d69c853 100644 --- a/sound/firewire/dice.c +++ b/sound/firewire/dice.c @@ -567,10 +567,14 @@ static int dice_hw_params(struct snd_pcm_substream *substream, return err; /* - * At rates above 96 kHz, pretend that the stream runs at half the - * actual sample rate with twice the number of channels; two samples - * of a channel are stored consecutively in the packet. Requires - * blocking mode and PCM buffer size should be aligned to SYT_INTERVAL. + * At 176.4/192.0 kHz, Dice has a quirk to transfer two PCM frames in + * one data block of AMDTP packet. Thus sampling transfer frequency is + * a half of PCM sampling frequency, i.e. PCM frames at 192.0 kHz are + * transferred on AMDTP packets at 96 kHz. Two successive samples of a + * channel are stored consecutively in the packet. This quirk is called + * as 'Dual Wire'. + * For this quirk, blocking mode is required and PCM buffer size should + * be aligned to SYT_INTERVAL. */ channels = params_channels(hw_params); if (rate_index > 4) { @@ -581,6 +585,9 @@ static int dice_hw_params(struct snd_pcm_substream *substream, rate /= 2; channels *= 2; + dice->stream.double_pcm_frames = true; + } else { + dice->stream.double_pcm_frames = false; } mode = rate_index_to_mode(rate_index); |