drm/sun4i: tcon: fix check of tcon->panel null pointer

Since tcon->panel is a pointer returned by of_drm_find_panel() need to
check if it is not NULL, hence a valid pointer.
IS_ERR() instead checks return error values, not NULL pointers.

Substitute "if (!IS_ERR(tcon->panel))" with "if (tcon->panel)".

Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181005215951.99003-1-giulio.benetti@micronovasrl.com

3 files changed, 5 insertions, 5 deletions

diff --git a/drivers/gpu/drm/sun4i/sun4i_lvds.c b/drivers/gpu/drm/sun4i/sun4i_lvds.c
index af7dcb6da351..e7eb0d1e17be 100644
--- a/drivers/gpu/drm/sun4i/sun4i_lvds.c
+++ b/drivers/gpu/drm/sun4i/sun4i_lvds.c
@@ -75,7 +75,7 @@ static void sun4i_lvds_encoder_enable(struct drm_encoder *encoder)
 
         DRM_DEBUG_DRIVER("Enabling LVDS output\n");
 
-        if (!IS_ERR(tcon->panel)) {
+        if (tcon->panel) {
                 drm_panel_prepare(tcon->panel);
                 drm_panel_enable(tcon->panel);
         }
@@ -88,7 +88,7 @@ static void sun4i_lvds_encoder_disable(struct drm_encoder *encoder)
 
         DRM_DEBUG_DRIVER("Disabling LVDS output\n");
 
-        if (!IS_ERR(tcon->panel)) {
+        if (tcon->panel) {
                 drm_panel_disable(tcon->panel);
                 drm_panel_unprepare(tcon->panel);
         }
diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
index bf068da6b12e..f4a22689eb54 100644
--- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
+++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
@@ -135,7 +135,7 @@ static void sun4i_rgb_encoder_enable(struct drm_encoder *encoder)
 
         DRM_DEBUG_DRIVER("Enabling RGB output\n");
 
-        if (!IS_ERR(tcon->panel)) {
+        if (tcon->panel) {
                 drm_panel_prepare(tcon->panel);
                 drm_panel_enable(tcon->panel);
         }
@@ -148,7 +148,7 @@ static void sun4i_rgb_encoder_disable(struct drm_encoder *encoder)
 
         DRM_DEBUG_DRIVER("Disabling RGB output\n");
 
-        if (!IS_ERR(tcon->panel)) {
+        if (tcon->panel) {
                 drm_panel_disable(tcon->panel);
                 drm_panel_unprepare(tcon->panel);
         }
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index c78cd35a1294..e4b3bd0307ef 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -555,7 +555,7 @@ static void sun4i_tcon0_mode_set_rgb(struct sun4i_tcon *tcon,
          * Following code is a way to avoid quirks all around TCON
          * and DOTCLOCK drivers.
          */
-        if (!IS_ERR(tcon->panel)) {
+        if (tcon->panel) {
                 struct drm_panel *panel = tcon->panel;
                 struct drm_connector *connector = panel->connector;
                 struct drm_display_info display_info = connector->display_info;