ALSA: hda: Fix max PCM level to 0 dB for AD1981_HP
BugLink: https://bugs.launchpad.net/bugs/461062
The original reporter states that PCM maxes at +12 dB and results in
very bad distortion. Cap PCM at 0 dB to resolve this symptom.
Signed-off-by: Daniel T Chen <crimsun@ubuntu.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/patch_analog.c b/sound/pci/hda/patch_analog.c
index 447eda1..1a36137 100644
--- a/sound/pci/hda/patch_analog.c
+++ b/sound/pci/hda/patch_analog.c
@@ -1789,6 +1789,14 @@
codec->patch_ops.init = ad1981_hp_init;
codec->patch_ops.unsol_event = ad1981_hp_unsol_event;
+ /* set the upper-limit for mixer amp to 0dB for avoiding the
+ * possible damage by overloading
+ */
+ snd_hda_override_amp_caps(codec, 0x11, HDA_INPUT,
+ (0x17 << AC_AMPCAP_OFFSET_SHIFT) |
+ (0x17 << AC_AMPCAP_NUM_STEPS_SHIFT) |
+ (0x05 << AC_AMPCAP_STEP_SIZE_SHIFT) |
+ (1 << AC_AMPCAP_MUTE_SHIFT));
break;
case AD1981_THINKPAD:
spec->mixers[0] = ad1981_thinkpad_mixers;