src/patches/suse-2.6.27.39/patches.drivers/alsa-post-ga-hda-reduce-click-noise

   1 From 05ff7e11b78f18ff6819d2c260b7bcc7da0c8f46 Mon Sep 17 00:00:00 2001
   2 From: Takashi Iwai <tiwai@suse.de>
   3 Subject: [PATCH] ALSA: hda - Reduce click noise at power-saving
   4 Patch-mainline:
   5 References: bnc#521190
   6
   7 Add some tricks to reduce the click noise at powering down to D3
   8 in the power saving mode on STAC/IDT codecs.
   9 The key seems to be to reset PINs before the power-down, and some
  10 delay before entering D3.  The needed delay is significantly long,
  11 but I don't know why.
  12
  13 Signed-off-by: Takashi Iwai <tiwai@suse.de>
  14
  15 ---
  16  sound/pci/hda/hda_codec.c      |    9 +++++++--
  17  sound/pci/hda/patch_sigmatel.c |   14 ++++++++++++++
  18  2 files changed, 21 insertions(+), 2 deletions(-)
  19
  20 --- a/sound/pci/hda/hda_codec.c
  21 +++ b/sound/pci/hda/hda_codec.c
  22 @@ -1979,9 +1979,14 @@ static void hda_set_power_state(struct h
  23         hda_nid_t nid;
  24         int i;
  25
  26 -       snd_hda_codec_write(codec, fg, 0, AC_VERB_SET_POWER_STATE,
  27 +       /* this delay seems necessary to avoid click noise at power-down */
  28 +       if (power_state == AC_PWRST_D3)
  29 +               msleep(100);
  30 +       snd_hda_codec_read(codec, fg, 0, AC_VERB_SET_POWER_STATE,
  31                             power_state);
  32 -       msleep(10); /* partial workaround for "azx_get_response timeout" */
  33 +       /* partial workaround for "azx_get_response timeout" */
  34 +       if (power_state == AC_PWRST_D0)
  35 +               msleep(10);
  36
  37         nid = codec->start_nid;
  38         for (i = 0; i < codec->num_nodes; i++, nid++) {
  39 --- a/sound/pci/hda/patch_sigmatel.c
  40 +++ b/sound/pci/hda/patch_sigmatel.c
  41 @@ -4268,6 +4268,20 @@ static int stac92xx_resume(struct hda_co
  42  static int stac92xx_suspend(struct hda_codec *codec, pm_message_t state)
  43  {
  44         struct sigmatel_spec *spec = codec->spec;
  45 +       int i;
  46 +       hda_nid_t nid;
  47 +
  48 +       /* reset each pin before powering down DAC/ADC to avoid click noise */
  49 +       nid = codec->start_nid;
  50 +       for (i = 0; i < codec->num_nodes; i++, nid++) {
  51 +               unsigned int wcaps = get_wcaps(codec, nid);
  52 +               unsigned int wid_type = (wcaps & AC_WCAP_TYPE) >>
  53 +                       AC_WCAP_TYPE_SHIFT;
  54 +               if (wid_type == AC_WID_PIN)
  55 +                       snd_hda_codec_read(codec, nid, 0,
  56 +                               AC_VERB_SET_PIN_WIDGET_CONTROL, 0);
  57 +       }
  58 +
  59         if (spec->eapd_mask)
  60                 stac_gpio_set(codec, spec->gpio_mask,
  61                                 spec->gpio_dir, spec->gpio_data &