Request pull

Daniel T Chen seven.steps at gmail.com
Wed Aug 5 21:11:56 UTC 2009


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The following changes since commit 
3f0467892d9c32f7466e280fc506272feda970e7:
   Takashi Iwai (1):
         ALSA: hda - Reduce click noise at power-saving

are available in the git repository at:

   git://kernel.ubuntu.com/dtchen/ubuntu-karmic.git powerdown

These changes address LP: #380892, #381693, #399750, specifically the
Sigmatel/IDT HDA codecs. Work is underway for Realtek, Analog Devices,
and Conexant HDA codecs.

Karmic testers with Sigmatel/IDT HDA codecs have confirmed the fix.

(Caveat: the patch below has whitespace munging.)



- From 3f0467892d9c32f7466e280fc506272feda970e7 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai at suse.de>
Date: Wed, 22 Jul 2009 12:39:24 +0200
Subject: [PATCH] ALSA: hda - Reduce click noise at power-saving

Add some tricks to reduce the click noise at powering down to D3
in the power saving mode on STAC/IDT codecs.
The key seems to be to reset PINs before the power-down, and some
delay before entering D3.  The needed delay is significantly long,
but I don't know why.

Signed-off-by: Takashi Iwai <tiwai at suse.de>
Signed-off-by: Daniel T Chen <seven.steps at gmail.com>
- ---
  sound/pci/hda/hda_codec.c      |    9 +++++++--
  sound/pci/hda/patch_sigmatel.c |   14 ++++++++++++++
  2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 88480c0..4d72e50 100644
- --- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -2356,9 +2356,14 @@ static void hda_set_power_state(struct hda_codec 
*codec, hda_nid_t fg,
         hda_nid_t nid;
         int i;

- -       snd_hda_codec_write(codec, fg, 0, AC_VERB_SET_POWER_STATE,
+       /* this delay seems necessary to avoid click noise at power-down 
*/
+       if (power_state == AC_PWRST_D3)
+               msleep(100);
+       snd_hda_codec_read(codec, fg, 0, AC_VERB_SET_POWER_STATE,
                             power_state);
- -       msleep(10); /* partial workaround for "azx_get_response timeout" 
*/
+       /* partial workaround for "azx_get_response timeout" */
+       if (power_state == AC_PWRST_D0)
+               msleep(10);

         nid = codec->start_nid;
         for (i = 0; i < codec->num_nodes; i++, nid++) {
diff --git a/sound/pci/hda/patch_sigmatel.c 
b/sound/pci/hda/patch_sigmatel.c
index 5383d8c..871c960 100644
- --- a/sound/pci/hda/patch_sigmatel.c
+++ b/sound/pci/hda/patch_sigmatel.c
@@ -4748,6 +4748,20 @@ static int stac92xx_hp_check_power_status(struct 
hda_codec *codec,
  static int stac92xx_suspend(struct hda_codec *codec, pm_message_t state)
  {
         struct sigmatel_spec *spec = codec->spec;
+       int i;
+       hda_nid_t nid;
+
+       /* reset each pin before powering down DAC/ADC to avoid click 
noise */
+       nid = codec->start_nid;
+       for (i = 0; i < codec->num_nodes; i++, nid++) {
+               unsigned int wcaps = get_wcaps(codec, nid);
+               unsigned int wid_type = (wcaps & AC_WCAP_TYPE) >>
+                       AC_WCAP_TYPE_SHIFT;
+               if (wid_type == AC_WID_PIN)
+                       snd_hda_codec_read(codec, nid, 0,
+                               AC_VERB_SET_PIN_WIDGET_CONTROL, 0);
+       }
+
         if (spec->eapd_mask)
                 stac_gpio_set(codec, spec->gpio_mask,
                                 spec->gpio_dir, spec->gpio_data &
- --
1.6.3.3
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