ALSA: hda: Fix 0 dB offset for HP laptops using CX20551 (Waikiki)

BugLink: https://launchpad.net/bugs/420578

The OR has verified that his hardware distorts because of the 0 dB
offset not corresponding to the highest PCM level. Fix this by capping
said PCM level to 0 dB similarly to what we do for CX20549 (Venice).

Reported-by: Mike Pontillo <pontillo@gmail.com>
Tested-by: Mike Pontillo <pontillo@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Daniel T Chen <crimsun@ubuntu.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 15 insertions, 0 deletions

diff --git a/sound/pci/hda/patch_conexant.c b/sound/pci/hda/patch_conexant.c
index 194a28c54992..61682e1d09da 100644
--- a/sound/pci/hda/patch_conexant.c
+++ b/sound/pci/hda/patch_conexant.c
@@ -1591,6 +1591,21 @@ static int patch_cxt5047(struct hda_codec *codec)
 #endif  
         }
         spec->vmaster_nid = 0x13;
+
+        switch (codec->subsystem_id >> 16) {
+        case 0x103c:
+                /* HP laptops have really bad sound over 0 dB on NID 0x10.
+                 * Fix max PCM level to 0 dB (originally it has 0x1e steps
+                 * with 0 dB offset 0x17)
+                 */
+                snd_hda_override_amp_caps(codec, 0x10, 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;
+        }
+
         return 0;
 }