diff --git a/drivers/gpu/drm/omapdrm/dss/base.c b/drivers/gpu/drm/omapdrm/dss/base.c
index 02c6ed97d632..89472715ee8f 100644
--- a/drivers/gpu/drm/omapdrm/dss/base.c
+++ b/drivers/gpu/drm/omapdrm/dss/base.c
@@ -235,6 +235,8 @@ void omapdss_device_disconnect(struct omap_dss_device *src,
 		src->dst = NULL;
 	}
 
+	WARN_ON(dst->state != OMAP_DSS_DISPLAY_DISABLED);
+
 	if (dst->driver)
 		dst->driver->disconnect(src, dst);
 	else
diff --git a/drivers/gpu/drm/omapdrm/dss/dpi.c b/drivers/gpu/drm/omapdrm/dss/dpi.c
index eeeea936f889..178b463c2d60 100644
--- a/drivers/gpu/drm/omapdrm/dss/dpi.c
+++ b/drivers/gpu/drm/omapdrm/dss/dpi.c
@@ -633,7 +633,6 @@ static void dpi_disconnect(struct omap_dss_device *src,
 			   struct omap_dss_device *dst)
 {
 	omapdss_device_disconnect(dst, dst->next);
-	omapdss_output_unset_device(dst);
 
 	dss_mgr_disconnect(dst);
 }
diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
index 9c617e35efd1..948e3b873523 100644
--- a/drivers/gpu/drm/omapdrm/dss/dsi.c
+++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
@@ -4903,7 +4903,6 @@ static void dsi_disconnect(struct omap_dss_device *src,
 			   struct omap_dss_device *dst)
 {
 	omapdss_device_disconnect(dst, dst->next);
-	omapdss_output_unset_device(dst);
 
 	dss_mgr_disconnect(dst);
 }
diff --git a/drivers/gpu/drm/omapdrm/dss/hdmi4.c b/drivers/gpu/drm/omapdrm/dss/hdmi4.c
index 22f8b74f5bf5..6616530d5fe6 100644
--- a/drivers/gpu/drm/omapdrm/dss/hdmi4.c
+++ b/drivers/gpu/drm/omapdrm/dss/hdmi4.c
@@ -450,7 +450,6 @@ static void hdmi_disconnect(struct omap_dss_device *src,
 			    struct omap_dss_device *dst)
 {
 	omapdss_device_disconnect(dst, dst->next);
-	omapdss_output_unset_device(dst);
 
 	dss_mgr_disconnect(dst);
 }
diff --git a/drivers/gpu/drm/omapdrm/dss/hdmi5.c b/drivers/gpu/drm/omapdrm/dss/hdmi5.c
index d8592d02a58d..f7e15edc05fc 100644
--- a/drivers/gpu/drm/omapdrm/dss/hdmi5.c
+++ b/drivers/gpu/drm/omapdrm/dss/hdmi5.c
@@ -455,7 +455,6 @@ static void hdmi_disconnect(struct omap_dss_device *src,
 			    struct omap_dss_device *dst)
 {
 	omapdss_device_disconnect(dst, dst->next);
-	omapdss_output_unset_device(dst);
 
 	dss_mgr_disconnect(dst);
 }
diff --git a/drivers/gpu/drm/omapdrm/dss/omapdss.h b/drivers/gpu/drm/omapdrm/dss/omapdss.h
index 600ac7c25724..8f9538e17ea4 100644
--- a/drivers/gpu/drm/omapdrm/dss/omapdss.h
+++ b/drivers/gpu/drm/omapdrm/dss/omapdss.h
@@ -522,7 +522,6 @@ int omap_dss_get_num_overlays(void);
 #define for_each_dss_output(d) \
 	while ((d = omapdss_device_get_next(d, OMAP_DSS_DEVICE_TYPE_OUTPUT)) != NULL)
 int omapdss_output_validate(struct omap_dss_device *out);
-int omapdss_output_unset_device(struct omap_dss_device *out);
 
 typedef void (*omap_dispc_isr_t) (void *arg, u32 mask);
 int omap_dispc_register_isr(omap_dispc_isr_t isr, void *arg, u32 mask);
diff --git a/drivers/gpu/drm/omapdrm/dss/output.c b/drivers/gpu/drm/omapdrm/dss/output.c
index be544dd48bf4..2da480be918d 100644
--- a/drivers/gpu/drm/omapdrm/dss/output.c
+++ b/drivers/gpu/drm/omapdrm/dss/output.c
@@ -24,8 +24,6 @@
 #include "dss.h"
 #include "omapdss.h"
 
-static DEFINE_MUTEX(output_lock);
-
 int omapdss_output_validate(struct omap_dss_device *out)
 {
 	if (out->next && out->output_type != out->next->type) {
@@ -37,25 +35,6 @@ int omapdss_output_validate(struct omap_dss_device *out)
 }
 EXPORT_SYMBOL(omapdss_output_validate);
 
-int omapdss_output_unset_device(struct omap_dss_device *out)
-{
-	int r = 0;
-
-	mutex_lock(&output_lock);
-
-	if (out->dst->state != OMAP_DSS_DISPLAY_DISABLED) {
-		dev_err(out->dev,
-			"device %s is not disabled, cannot unset device\n",
-			out->dst->name);
-		r = -EINVAL;
-	}
-
-	mutex_unlock(&output_lock);
-
-	return r;
-}
-EXPORT_SYMBOL(omapdss_output_unset_device);
-
 int dss_install_mgr_ops(struct dss_device *dss,
 			const struct dss_mgr_ops *mgr_ops,
 			struct omap_drm_private *priv)
diff --git a/drivers/gpu/drm/omapdrm/dss/sdi.c b/drivers/gpu/drm/omapdrm/dss/sdi.c
index 2101a697a08a..764299cafbe2 100644
--- a/drivers/gpu/drm/omapdrm/dss/sdi.c
+++ b/drivers/gpu/drm/omapdrm/dss/sdi.c
@@ -274,7 +274,6 @@ static void sdi_disconnect(struct omap_dss_device *src,
 			   struct omap_dss_device *dst)
 {
 	omapdss_device_disconnect(dst, dst->next);
-	omapdss_output_unset_device(dst);
 
 	dss_mgr_disconnect(dst);
 }
diff --git a/drivers/gpu/drm/omapdrm/dss/venc.c b/drivers/gpu/drm/omapdrm/dss/venc.c
index e673f3e78c69..c2811c425195 100644
--- a/drivers/gpu/drm/omapdrm/dss/venc.c
+++ b/drivers/gpu/drm/omapdrm/dss/venc.c
@@ -713,7 +713,6 @@ static void venc_disconnect(struct omap_dss_device *src,
 			    struct omap_dss_device *dst)
 {
 	omapdss_device_disconnect(dst, dst->next);
-	omapdss_output_unset_device(dst);
 
 	dss_mgr_disconnect(dst);
 }