3 files changed, 33 insertions, 1 deletions

diff --git a/sound/pci/ac97/ac97_codec.c b/sound/pci/ac97/ac97_codec.c
index 124c1bc4cb92..38b6c65d40c3 100644
--- a/sound/pci/ac97/ac97_codec.c
+++ b/sound/pci/ac97/ac97_codec.c
@@ -150,7 +150,7 @@ static const struct ac97_codec_id snd_ac97_codec_ids[] = {
 { 0x49544561, 0xffffffff, "IT2646E",            patch_it2646,   NULL },
 { 0x4e534300, 0xffffffff, "LM4540,43,45,46,48", NULL,           NULL }, // only guess --jk
 { 0x4e534331, 0xffffffff, "LM4549",             NULL,           NULL },
-{ 0x4e534350, 0xffffffff, "LM4550",             NULL,           NULL },
+{ 0x4e534350, 0xffffffff, "LM4550",             patch_lm4550,   NULL }, // volume wrap fix 
 { 0x50534304, 0xffffffff, "UCB1400",            NULL,           NULL },
 { 0x53494c20, 0xffffffe0, "Si3036,8",           mpatch_si3036,  mpatch_si3036, AC97_MODEM_PATCH },
 { 0x54524102, 0xffffffff, "TR28022",            NULL,           NULL },
diff --git a/sound/pci/ac97/ac97_patch.c b/sound/pci/ac97/ac97_patch.c
index 8bc79cbe3215..5c03b4b6f5c1 100644
--- a/sound/pci/ac97/ac97_patch.c
+++ b/sound/pci/ac97/ac97_patch.c
@@ -2825,3 +2825,34 @@ int mpatch_si3036(struct snd_ac97 * ac97)
         snd_ac97_write_cache(ac97, 0x68, 0);
         return 0;
 }
+
+/*
+ * LM 4550 Codec
+ *
+ * We use a static resolution table since LM4550 codec cannot be
+ * properly autoprobed to determine the resolution via
+ * check_volume_resolution().
+ */
+
+static struct snd_ac97_res_table lm4550_restbl[] = {
+        { AC97_MASTER, 0x1f1f },
+        { AC97_HEADPHONE, 0x1f1f },
+        { AC97_MASTER_MONO, 0x001f },
+        { AC97_PC_BEEP, 0x001f },       /* LSB is ignored */
+        { AC97_PHONE, 0x001f },
+        { AC97_PHONE, 0x001f },
+        { AC97_MIC, 0x001f },
+        { AC97_LINE, 0x1f1f },
+        { AC97_CD, 0x1f1f },
+        { AC97_VIDEO, 0x1f1f },
+        { AC97_AUX, 0x1f1f },
+        { AC97_PCM, 0x1f1f },
+        { AC97_REC_GAIN, 0x0f0f },
+        { } /* terminator */
+};
+
+int patch_lm4550(struct snd_ac97 *ac97)
+{
+        ac97->res_table = lm4550_restbl;
+        return 0;
+}
diff --git a/sound/pci/ac97/ac97_patch.h b/sound/pci/ac97/ac97_patch.h
index 5060cb6f2ec3..adcaa04586cb 100644
--- a/sound/pci/ac97/ac97_patch.h
+++ b/sound/pci/ac97/ac97_patch.h
@@ -59,3 +59,4 @@ int patch_vt1616(struct snd_ac97 * ac97);
 int patch_vt1617a(struct snd_ac97 * ac97);
 int patch_it2646(struct snd_ac97 * ac97);
 int mpatch_si3036(struct snd_ac97 * ac97);
+int patch_lm4550(struct snd_ac97 * ac97);