releases/2.6.32.12/alsa-hda-fix-0-db-offset-for-lenovo-thinkpad-models-using-ad1981.patch

   1 From b8e80cf386419453678b01bef830f53445ebb15d Mon Sep 17 00:00:00 2001
   2 From: Daniel T Chen <crimsun@ubuntu.com>
   3 Date: Tue, 30 Mar 2010 13:29:28 -0400
   4 Subject: ALSA: hda: Fix 0 dB offset for Lenovo Thinkpad models using AD1981
   5
   6 From: Daniel T Chen <crimsun@ubuntu.com>
   7
   8 commit b8e80cf386419453678b01bef830f53445ebb15d upstream.
   9
  10 BugLink: https://launchpad.net/bugs/551606
  11
  12 The OR's hardware distorts at PCM 100% because it does not correspond to
  13 0 dB. Fix this in patch_ad1981() for all models using the Thinkpad
  14 quirk.
  15
  16 Reported-by: Jane Silber
  17 Signed-off-by: Daniel T Chen <crimsun@ubuntu.com>
  18 Signed-off-by: Takashi Iwai <tiwai@suse.de>
  19 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  20
  21 ---
  22  sound/pci/hda/patch_analog.c |    8 ++++++++
  23  1 file changed, 8 insertions(+)
  24
  25 --- a/sound/pci/hda/patch_analog.c
  26 +++ b/sound/pci/hda/patch_analog.c
  27 @@ -1789,6 +1789,14 @@ static int patch_ad1981(struct hda_codec
  28         case AD1981_THINKPAD:
  29                 spec->mixers[0] = ad1981_thinkpad_mixers;
  30                 spec->input_mux = &ad1981_thinkpad_capture_source;
  31 +               /* set the upper-limit for mixer amp to 0dB for avoiding the
  32 +                * possible damage by overloading
  33 +                */
  34 +               snd_hda_override_amp_caps(codec, 0x11, HDA_INPUT,
  35 +                                         (0x17 << AC_AMPCAP_OFFSET_SHIFT) |
  36 +                                         (0x17 << AC_AMPCAP_NUM_STEPS_SHIFT) |
  37 +                                         (0x05 << AC_AMPCAP_STEP_SIZE_SHIFT) |
  38 +                                         (1 << AC_AMPCAP_MUTE_SHIFT));
  39                 break;
  40         case AD1981_TOSHIBA:
  41                 spec->mixers[0] = ad1981_hp_mixers;