diff --git a/drivers/gpu/drm/armada/armada_slave.c b/drivers/gpu/drm/armada/armada_slave.c
index 00d0fac..a58f4f9 100644
--- a/drivers/gpu/drm/armada/armada_slave.c
+++ b/drivers/gpu/drm/armada/armada_slave.c
@@ -42,6 +42,14 @@ static void armada_drm_slave_destroy(struct drm_encoder *enc)
 	kfree(slave);
 }
 
+static void armada_drm_slave_mode_set(struct drm_encoder *encoder,
+				      struct drm_display_mode *mode,
+				      struct drm_display_mode *adjusted_mode)
+{
+	drm_i2c_encoder_mode_set(encoder, mode, adjusted_mode);
+}
+
+
 static const struct drm_encoder_funcs armada_drm_slave_encoder_funcs = {
 	.destroy	= armada_drm_slave_destroy,
 };
@@ -59,7 +67,7 @@ static const struct drm_encoder_helper_funcs drm_slave_encoder_helpers = {
 	.mode_fixup = drm_i2c_encoder_mode_fixup,
 	.prepare = drm_i2c_encoder_prepare,
 	.commit = drm_i2c_encoder_commit,
-	.mode_set = drm_i2c_encoder_mode_set,
+	.mode_set = armada_drm_slave_mode_set,
 	.detect = drm_i2c_encoder_detect,
 };
 
diff --git a/drivers/gpu/drm/drm_encoder_slave.c b/drivers/gpu/drm/drm_encoder_slave.c
index d18b88b..41edd73 100644
--- a/drivers/gpu/drm/drm_encoder_slave.c
+++ b/drivers/gpu/drm/drm_encoder_slave.c
@@ -157,8 +157,8 @@ void drm_i2c_encoder_commit(struct drm_encoder *encoder)
 EXPORT_SYMBOL(drm_i2c_encoder_commit);
 
 void drm_i2c_encoder_mode_set(struct drm_encoder *encoder,
-		struct drm_display_mode *mode,
-		struct drm_display_mode *adjusted_mode)
+		const struct drm_display_mode *mode,
+		const struct drm_display_mode *adjusted_mode)
 {
 	get_slave_funcs(encoder)->mode_set(encoder, mode, adjusted_mode);
 }
diff --git a/drivers/gpu/drm/i2c/adv7511.c b/drivers/gpu/drm/i2c/adv7511.c
index 61aa824..534f0a3 100644
--- a/drivers/gpu/drm/i2c/adv7511.c
+++ b/drivers/gpu/drm/i2c/adv7511.c
@@ -639,7 +639,7 @@ adv7511_encoder_detect(struct drm_encoder *encoder,
 }
 
 static int adv7511_encoder_mode_valid(struct drm_encoder *encoder,
-				      struct drm_display_mode *mode)
+				      const struct drm_display_mode *mode)
 {
 	if (mode->clock > 165000)
 		return MODE_CLOCK_HIGH;
@@ -648,8 +648,8 @@ static int adv7511_encoder_mode_valid(struct drm_encoder *encoder,
 }
 
 static void adv7511_encoder_mode_set(struct drm_encoder *encoder,
-				     struct drm_display_mode *mode,
-				     struct drm_display_mode *adj_mode)
+				     const struct drm_display_mode *mode,
+				     const struct drm_display_mode *adj_mode)
 {
 	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
 	unsigned int low_refresh_rate;
diff --git a/drivers/gpu/drm/i2c/ch7006_drv.c b/drivers/gpu/drm/i2c/ch7006_drv.c
index 51fa323..77c6c95 100644
--- a/drivers/gpu/drm/i2c/ch7006_drv.c
+++ b/drivers/gpu/drm/i2c/ch7006_drv.c
@@ -102,7 +102,7 @@ static bool ch7006_encoder_mode_fixup(struct drm_encoder *encoder,
 }
 
 static int ch7006_encoder_mode_valid(struct drm_encoder *encoder,
-				     struct drm_display_mode *mode)
+				     const struct drm_display_mode *mode)
 {
 	if (ch7006_lookup_mode(encoder, mode))
 		return MODE_OK;
@@ -111,8 +111,8 @@ static int ch7006_encoder_mode_valid(struct drm_encoder *encoder,
 }
 
 static void ch7006_encoder_mode_set(struct drm_encoder *encoder,
-				     struct drm_display_mode *drm_mode,
-				     struct drm_display_mode *adjusted_mode)
+				     const struct drm_display_mode *drm_mode,
+				     const struct drm_display_mode *adjusted_mode)
 {
 	struct i2c_client *client = drm_i2c_encoder_get_client(encoder);
 	struct ch7006_priv *priv = to_ch7006_priv(encoder);
diff --git a/drivers/gpu/drm/i2c/sil164_drv.c b/drivers/gpu/drm/i2c/sil164_drv.c
index 002ce78..dd7cea2 100644
--- a/drivers/gpu/drm/i2c/sil164_drv.c
+++ b/drivers/gpu/drm/i2c/sil164_drv.c
@@ -262,7 +262,7 @@ sil164_encoder_mode_fixup(struct drm_encoder *encoder,
 
 static int
 sil164_encoder_mode_valid(struct drm_encoder *encoder,
-			  struct drm_display_mode *mode)
+			  const struct drm_display_mode *mode)
 {
 	struct sil164_priv *priv = to_sil164_priv(encoder);
 
@@ -278,8 +278,8 @@ sil164_encoder_mode_valid(struct drm_encoder *encoder,
 
 static void
 sil164_encoder_mode_set(struct drm_encoder *encoder,
-			struct drm_display_mode *mode,
-			struct drm_display_mode *adjusted_mode)
+			const struct drm_display_mode *mode,
+			const struct drm_display_mode *adjusted_mode)
 {
 	struct sil164_priv *priv = to_sil164_priv(encoder);
 	bool duallink = adjusted_mode->clock > 165000;
diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c
index 5febffd..f697443 100644
--- a/drivers/gpu/drm/i2c/tda998x_drv.c
+++ b/drivers/gpu/drm/i2c/tda998x_drv.c
@@ -632,7 +632,8 @@ tda998x_write_aif(struct tda998x_priv *priv, struct tda998x_encoder_params *p)
 }
 
 static void
-tda998x_write_avi(struct tda998x_priv *priv, struct drm_display_mode *mode)
+tda998x_write_avi(struct tda998x_priv *priv,
+		  const struct drm_display_mode *mode)
 {
 	u8 buf[PB(HDMI_AVI_INFOFRAME_SIZE) + 1];
 
@@ -662,7 +663,8 @@ static void tda998x_audio_mute(struct tda998x_priv *priv, bool on)
 
 static void
 tda998x_configure_audio(struct tda998x_priv *priv,
-		struct drm_display_mode *mode, struct tda998x_encoder_params *p)
+			const struct drm_display_mode *mode,
+			struct tda998x_encoder_params *p)
 {
 	uint8_t buf[6], clksel_aip, clksel_fs, cts_n, adiv;
 	uint32_t n;
@@ -825,7 +827,7 @@ tda998x_encoder_mode_fixup(struct drm_encoder *encoder,
 }
 
 static int tda998x_encoder_mode_valid(struct tda998x_priv *priv,
-				      struct drm_display_mode *mode)
+				      const struct drm_display_mode *mode)
 {
 	if (mode->clock > 150000)
 		return MODE_CLOCK_HIGH;
@@ -838,8 +840,8 @@ static int tda998x_encoder_mode_valid(struct tda998x_priv *priv,
 
 static void
 tda998x_encoder_mode_set(struct tda998x_priv *priv,
-			 struct drm_display_mode *mode,
-			 struct drm_display_mode *adjusted_mode)
+			 const struct drm_display_mode *mode,
+			 const struct drm_display_mode *adjusted_mode)
 {
 	uint16_t ref_pix, ref_line, n_pix, n_line;
 	uint16_t hs_pix_s, hs_pix_e;
@@ -1176,15 +1178,15 @@ static void tda998x_encoder_slave_dpms(struct drm_encoder *encoder, int mode)
 }
 
 static int tda998x_encoder_slave_mode_valid(struct drm_encoder *encoder,
-					    struct drm_display_mode *mode)
+					    const struct drm_display_mode *mode)
 {
 	return tda998x_encoder_mode_valid(to_tda998x_priv(encoder), mode);
 }
 
 static void
 tda998x_encoder_slave_mode_set(struct drm_encoder *encoder,
-			       struct drm_display_mode *mode,
-			       struct drm_display_mode *adjusted_mode)
+			       const struct drm_display_mode *mode,
+			       const struct drm_display_mode *adjusted_mode)
 {
 	tda998x_encoder_mode_set(to_tda998x_priv(encoder), mode, adjusted_mode);
 }
diff --git a/drivers/gpu/drm/msm/edp/edp_ctrl.c b/drivers/gpu/drm/msm/edp/edp_ctrl.c
index 0ec5abd..f5ae491 100644
--- a/drivers/gpu/drm/msm/edp/edp_ctrl.c
+++ b/drivers/gpu/drm/msm/edp/edp_ctrl.c
@@ -1280,7 +1280,7 @@ unlock_ret:
 }
 
 int msm_edp_ctrl_timing_cfg(struct edp_ctrl *ctrl,
-				const struct drm_display_mode *mode,
+				const const struct drm_display_mode *mode,
 				const struct drm_display_info *info)
 {
 	u32 hstart_from_sync, vstart_from_sync;
diff --git a/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c b/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
index 731d74e..c77ffe3 100644
--- a/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
+++ b/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
@@ -309,7 +309,7 @@ static int nv17_tv_get_modes(struct drm_encoder *encoder,
 }
 
 static int nv17_tv_mode_valid(struct drm_encoder *encoder,
-			      struct drm_display_mode *mode)
+			      const struct drm_display_mode *mode)
 {
 	struct nv17_tv_norm_params *tv_norm = get_tv_norm(encoder);
 
@@ -524,7 +524,7 @@ static void nv17_tv_mode_set(struct drm_encoder *encoder,
 			tv_regs->tv_enc[i] = tv_norm->tv_enc_mode.tv_enc[i];
 
 	} else {
-		struct drm_display_mode *output_mode =
+		const struct drm_display_mode *output_mode =
 						&tv_norm->ctv_enc_mode.mode;
 
 		/* The registers in PRAMDAC+0xc00 control some timings and CSC
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_slave.c b/drivers/gpu/drm/tilcdc/tilcdc_slave.c
index 3775fd4..5842845 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_slave.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_slave.c
@@ -96,6 +96,12 @@ static bool slave_encoder_fixup(struct drm_encoder *encoder,
 	return drm_i2c_encoder_mode_fixup(encoder, mode, adjusted_mode);
 }
 
+static void slave_encoder_mode_set(struct drm_encoder *encoder,
+				   struct drm_display_mode *mode,
+				   struct drm_display_mode *adjusted_mode)
+{
+	drm_i2c_encoder_mode_set(encoder, mode, adjusted_mode);
+}
 
 static const struct drm_encoder_funcs slave_encoder_funcs = {
 		.destroy        = slave_encoder_destroy,
@@ -106,7 +112,7 @@ static const struct drm_encoder_helper_funcs slave_encoder_helper_funcs = {
 		.mode_fixup     = slave_encoder_fixup,
 		.prepare        = slave_encoder_prepare,
 		.commit         = drm_i2c_encoder_commit,
-		.mode_set       = drm_i2c_encoder_mode_set,
+		.mode_set       = slave_encoder_mode_set,
 		.save           = drm_i2c_encoder_save,
 		.restore        = drm_i2c_encoder_restore,
 };
diff --git a/include/drm/drm_encoder_slave.h b/include/drm/drm_encoder_slave.h
index 8b9cc36..c99c636 100644
--- a/include/drm/drm_encoder_slave.h
+++ b/include/drm/drm_encoder_slave.h
@@ -57,10 +57,10 @@ struct drm_encoder_slave_funcs {
 			   const struct drm_display_mode *mode,
 			   struct drm_display_mode *adjusted_mode);
 	int (*mode_valid)(struct drm_encoder *encoder,
-			  struct drm_display_mode *mode);
+			  const struct drm_display_mode *mode);
 	void (*mode_set)(struct drm_encoder *encoder,
-			 struct drm_display_mode *mode,
-			 struct drm_display_mode *adjusted_mode);
+			 const struct drm_display_mode *mode,
+			 const struct drm_display_mode *adjusted_mode);
 
 	enum drm_connector_status (*detect)(struct drm_encoder *encoder,
 					    struct drm_connector *connector);
@@ -171,8 +171,8 @@ bool drm_i2c_encoder_mode_fixup(struct drm_encoder *encoder,
 void drm_i2c_encoder_prepare(struct drm_encoder *encoder);
 void drm_i2c_encoder_commit(struct drm_encoder *encoder);
 void drm_i2c_encoder_mode_set(struct drm_encoder *encoder,
-		struct drm_display_mode *mode,
-		struct drm_display_mode *adjusted_mode);
+		const struct drm_display_mode *mode,
+		const struct drm_display_mode *adjusted_mode);
 enum drm_connector_status drm_i2c_encoder_detect(struct drm_encoder *encoder,
 	    struct drm_connector *connector);
 void drm_i2c_encoder_save(struct drm_encoder *encoder);
