diff --git a/sound/soc/sof/intel/bdw.c b/sound/soc/sof/intel/bdw.c
index 47d3896329d25b..dc21d1fac43323 100644
--- a/sound/soc/sof/intel/bdw.c
+++ b/sound/soc/sof/intel/bdw.c
@@ -730,7 +730,7 @@ static struct snd_soc_dai_driver bdw_dai[] = {
 },
 };
 
-struct snd_sof_dai_drv bdw_dai_drv = {
+static struct snd_sof_dai_drv bdw_dai_drv = {
 	.drv = bdw_dai,
 	.num_drv = ARRAY_SIZE(bdw_dai)
 };
diff --git a/sound/soc/sof/intel/byt.c b/sound/soc/sof/intel/byt.c
index 77a2c7a041cc96..49ec019b45d0fa 100644
--- a/sound/soc/sof/intel/byt.c
+++ b/sound/soc/sof/intel/byt.c
@@ -799,12 +799,12 @@ static struct snd_soc_dai_driver byt_dai[] = {
 },
 };
 
-struct snd_sof_dai_drv byt_dai_drv = {
+static struct snd_sof_dai_drv byt_dai_drv = {
 	.drv = byt_dai,
 	.num_drv = 3, /* we have only 3 SSPs on byt*/
 };
 
-struct snd_sof_dai_drv cht_dai_drv = {
+static struct snd_sof_dai_drv cht_dai_drv = {
 	.drv = byt_dai,
 	/* all 6 SSPs may be available for cherrytrail */
 	.num_drv = ARRAY_SIZE(byt_dai),
diff --git a/sound/soc/sof/intel/hda-dai.c b/sound/soc/sof/intel/hda-dai.c
index 091fcc1a7e66a0..9df9c4990eb109 100644
--- a/sound/soc/sof/intel/hda-dai.c
+++ b/sound/soc/sof/intel/hda-dai.c
@@ -10,6 +10,7 @@
 
 #include <sound/pcm_params.h>
 #include "../sof-priv.h"
+#include "hda.h"
 
 #define SKL_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE | \
 	SNDRV_PCM_FMTBIT_S32_LE)
diff --git a/sound/soc/sof/intel/hsw.c b/sound/soc/sof/intel/hsw.c
index 5e2c50b47b7502..1a8cbd3af50e13 100644
--- a/sound/soc/sof/intel/hsw.c
+++ b/sound/soc/sof/intel/hsw.c
@@ -730,7 +730,7 @@ static struct snd_soc_dai_driver hsw_dai[] = {
 },
 };
 
-struct snd_sof_dai_drv hsw_dai_drv = {
+static struct snd_sof_dai_drv hsw_dai_drv = {
 	.drv = hsw_dai,
 	.num_drv = ARRAY_SIZE(hsw_dai)
 };
diff --git a/sound/soc/sof/intel/skl.c b/sound/soc/sof/intel/skl.c
index adb85a579b697e..86097bbea1ad58 100644
--- a/sound/soc/sof/intel/skl.c
+++ b/sound/soc/sof/intel/skl.c
@@ -40,11 +40,6 @@ static const struct snd_sof_debugfs_map skl_dsp_debugfs[] = {
 	{"dsp", HDA_DSP_BAR,  0, 0x10000},
 };
 
-int skl_run_firmware(struct snd_sof_dev *sdev)
-{
-	return 0;
-}
-
 /* skylake ops */
 struct snd_sof_dsp_ops sof_skl_ops = {
 	/* probe and remove */