[PATCH 07/12] drm/rockchip: lvds: Helpers should return decent values

[Miquel Raynal <miquel.raynal@bootlin.com>]

Return errors instead of returning void from internal helpers. When
these helpers are called, check the returned value and print an error
message in this case.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/gpu/drm/rockchip/rockchip_lvds.c | 31 ++++++++++++++++++------
 1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_lvds.c b/drivers/gpu/drm/rockchip/rockchip_lvds.c
index 0d2902b0d990..6365a2c883c3 100644
--- a/drivers/gpu/drm/rockchip/rockchip_lvds.c
+++ b/drivers/gpu/drm/rockchip/rockchip_lvds.c
@@ -215,8 +215,8 @@ struct drm_connector_helper_funcs rockchip_lvds_connector_helper_funcs = {
 	.get_modes = rockchip_lvds_connector_get_modes,
 };
 
-static void rk3288_lvds_grf_config(struct drm_encoder *encoder,
-				   struct drm_display_mode *mode)
+static int rk3288_lvds_grf_config(struct drm_encoder *encoder,
+				  struct drm_display_mode *mode)
 {
 	struct rockchip_lvds *lvds = encoder_to_lvds(encoder);
 	u8 pin_hsync = (mode->flags & DRM_MODE_FLAG_PHSYNC) ? 1 : 0;
@@ -241,10 +241,10 @@ static void rk3288_lvds_grf_config(struct drm_encoder *encoder,
 	val |= (pin_dclk << 8) | (pin_hsync << 9);
 	val |= (0xffff << 16);
 	ret = regmap_write(lvds->grf, RK3288_LVDS_GRF_SOC_CON7, val);
-	if (ret != 0) {
+	if (ret)
 		DRM_DEV_ERROR(lvds->dev, "Could not write to GRF: %d\n", ret);
-		return;
-	}
+
+	return ret;
 }
 
 static int rk3288_lvds_set_vop_source(struct rockchip_lvds *lvds,
@@ -288,13 +288,28 @@ static void rk3288_lvds_encoder_enable(struct drm_encoder *encoder)
 	int ret;
 
 	drm_panel_prepare(lvds->panel);
+
 	ret = rk3288_lvds_poweron(lvds);
 	if (ret < 0) {
-		DRM_DEV_ERROR(lvds->dev, "failed to power on lvds: %d\n", ret);
+		DRM_DEV_ERROR(lvds->dev, "failed to power on LVDS: %d\n", ret);
 		drm_panel_unprepare(lvds->panel);
+		return;
 	}
-	rk3288_lvds_grf_config(encoder, mode);
-	rk3288_lvds_set_vop_source(lvds, encoder);
+
+	ret = rk3288_lvds_grf_config(encoder, mode);
+	if (ret) {
+		DRM_DEV_ERROR(lvds->dev, "failed to configure LVDS: %d\n", ret);
+		drm_panel_unprepare(lvds->panel);
+		return;
+	}
+
+	ret = rk3288_lvds_set_vop_source(lvds, encoder);
+	if (ret) {
+		DRM_DEV_ERROR(lvds->dev, "failed to set VOP source: %d\n", ret);
+		drm_panel_unprepare(lvds->panel);
+		return;
+	}
+
 	drm_panel_enable(lvds->panel);
 }
 
-- 
2.20.1