From 9a2a5a7a94e08b879c4f67dfe2032c9eb0b3aff3 Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Tue, 24 Dec 2019 15:38:56 +0100
Subject: drm/rockchip: lvds: improve error handling in helper functions
Git-commit: 2258d53a6696eec6a294af5627c45c8aafe001a8
Patch-mainline: v5.6-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

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 and not blindly continue.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20191224143900.23567-8-miquel.raynal@bootlin.com
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 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 511c6c9e26a7..b3a7530f5c92 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;
+	}
+
+	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;
 	}
-	rk3288_lvds_grf_config(encoder, mode);
-	rk3288_lvds_set_vop_source(lvds, encoder);
+
+	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);
 }
 
-- 
2.28.0