git.ipfire.org Git - thirdparty/kernel/stable-queue.git/blob

   1 From 65845f29bec6bc17f80eff25c3bc39bcf3be9bf9 Mon Sep 17 00:00:00 2001
   2 From: Takashi Sakamoto <o-takashi@sakamocchi.jp>
   3 Date: Fri, 29 Aug 2014 13:40:45 +0900
   4 Subject: ALSA: firewire-lib/dice: add arrangements of PCM pointer and interrupts for Dice quirk
   5
   6 From: Takashi Sakamoto <o-takashi@sakamocchi.jp>
   7
   8 commit 65845f29bec6bc17f80eff25c3bc39bcf3be9bf9 upstream.
   9
  10 In IEC 61883-6, one data block transfers one event. In ALSA, the event equals one PCM frame,
  11 hence one data block transfers one PCM frame. But Dice has a quirk at higher sampling rate
  12 (176.4/192.0 kHz) that one data block transfers two PCM frames.
  13
  14 Commit 10550bea44a8 ("ALSA: dice/firewire-lib: Keep dualwire mode but obsolete
  15 CIP_HI_DUALWIRE") moved some codes related to this quirk into Dice driver. But the commit
  16 forgot to add arrangements for PCM period interrupts and DMA pointer updates. As a result, Dice
  17 driver cannot work correctly at higher sampling rate.
  18
  19 This commit adds 'double_pcm_frames' parameter to amdtp structure for this quirk. When this
  20 parameter is set, PCM period interrupts and DMA pointer updates occur at double speed than in
  21 IEC 61883-6.
  22
  23 Reported-by: Daniel Robbins <drobbins@funtoo.org>
  24 Fixes: 10550bea44a8 ("ALSA: dice/firewire-lib: Keep dualwire mode but obsolete CIP_HI_DUALWIRE")
  25 Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
  26 Signed-off-by: Takashi Iwai <tiwai@suse.de>
  27 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  28
  29 ---
  30  sound/firewire/amdtp.c |   11 ++++++++++-
  31  sound/firewire/amdtp.h |    1 +
  32  sound/firewire/dice.c  |   15 +++++++++++----
  33  3 files changed, 22 insertions(+), 5 deletions(-)
  34
  35 --- a/sound/firewire/amdtp.c
  36 +++ b/sound/firewire/amdtp.c
  37 @@ -507,7 +507,16 @@ static void amdtp_pull_midi(struct amdtp
  38  static void update_pcm_pointers(struct amdtp_stream *s,
  39                                 struct snd_pcm_substream *pcm,
  40                                 unsigned int frames)
  41 -{      unsigned int ptr;
  42 +{
  43 +       unsigned int ptr;
  44 +
  45 +       /*
  46 +        * In IEC 61883-6, one data block represents one event. In ALSA, one
  47 +        * event equals to one PCM frame. But Dice has a quirk to transfer
  48 +        * two PCM frames in one data block.
  49 +        */
  50 +       if (s->double_pcm_frames)
  51 +               frames *= 2;
  52
  53         ptr = s->pcm_buffer_pointer + frames;
  54         if (ptr >= pcm->runtime->buffer_size)
  55 --- a/sound/firewire/amdtp.h
  56 +++ b/sound/firewire/amdtp.h
  57 @@ -125,6 +125,7 @@ struct amdtp_stream {
  58         unsigned int pcm_buffer_pointer;
  59         unsigned int pcm_period_pointer;
  60         bool pointer_flush;
  61 +       bool double_pcm_frames;
  62
  63         struct snd_rawmidi_substream *midi[AMDTP_MAX_CHANNELS_FOR_MIDI * 8];
  64
  65 --- a/sound/firewire/dice.c
  66 +++ b/sound/firewire/dice.c
  67 @@ -567,10 +567,14 @@ static int dice_hw_params(struct snd_pcm
  68                 return err;
  69
  70         /*
  71 -        * At rates above 96 kHz, pretend that the stream runs at half the
  72 -        * actual sample rate with twice the number of channels; two samples
  73 -        * of a channel are stored consecutively in the packet. Requires
  74 -        * blocking mode and PCM buffer size should be aligned to SYT_INTERVAL.
  75 +        * At 176.4/192.0 kHz, Dice has a quirk to transfer two PCM frames in
  76 +        * one data block of AMDTP packet. Thus sampling transfer frequency is
  77 +        * a half of PCM sampling frequency, i.e. PCM frames at 192.0 kHz are
  78 +        * transferred on AMDTP packets at 96 kHz. Two successive samples of a
  79 +        * channel are stored consecutively in the packet. This quirk is called
  80 +        * as 'Dual Wire'.
  81 +        * For this quirk, blocking mode is required and PCM buffer size should
  82 +        * be aligned to SYT_INTERVAL.
  83          */
  84         channels = params_channels(hw_params);
  85         if (rate_index > 4) {
  86 @@ -581,6 +585,9 @@ static int dice_hw_params(struct snd_pcm
  87
  88                 rate /= 2;
  89                 channels *= 2;
  90 +               dice->stream.double_pcm_frames = true;
  91 +       } else {
  92 +               dice->stream.double_pcm_frames = false;
  93         }
  94
  95         mode = rate_index_to_mode(rate_index);