linux-kernel - [PATCH] drm/mediatek: Test component initialization earlier in the function mtk_drm_crtc

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Date:   Mon, 12 Jul 2021 20:12:09 +0200
From:   Dafna Hirschfeld <dafna.hirschfeld@...labora.com>
To:     dri-devel@...ts.freedesktop.org,
        linux-mediatek@...ts.infradead.org, linux-kernel@...r.kernel.org
Cc:     dafna.hirschfeld@...labora.com, kernel@...labora.com,
        dafna3@...il.com, chunkuang.hu@...nel.org, p.zabel@...gutronix.de,
        airlied@...ux.ie, daniel@...ll.ch, enric.balletbo@...labora.com,
        laurent.pinchart@...asonboard.com
Subject: [PATCH] drm/mediatek: Test component initialization earlier in the function mtk_drm_crtc_create

The initialization is currently tested in a later stage in
the function for no reason.
In addition, the test '!comp' will never fail since comp is
set with the '&' operator. Instead, test if a comp was not
initialized by testing "!comp->dev".

Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@...labora.com>
---
 drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index 474efb844249..06f40e589922 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -755,14 +755,22 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 	for (i = 0; i < path_len; i++) {
 		enum mtk_ddp_comp_id comp_id = path[i];
 		struct device_node *node;
+		struct mtk_ddp_comp *comp;
 
 		node = priv->comp_node[comp_id];
+		comp = &priv->ddp_comp[comp_id];
+
 		if (!node) {
 			dev_info(dev,
 				 "Not creating crtc %d because component %d is disabled or missing\n",
 				 pipe, comp_id);
 			return 0;
 		}
+
+		if (!comp->dev) {
+			dev_err(dev, "Component %pOF not initialized\n", node);
+			return -ENODEV;
+		}
 	}
 
 	mtk_crtc = devm_kzalloc(dev, sizeof(*mtk_crtc), GFP_KERNEL);
@@ -787,16 +795,8 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 	for (i = 0; i < mtk_crtc->ddp_comp_nr; i++) {
 		enum mtk_ddp_comp_id comp_id = path[i];
 		struct mtk_ddp_comp *comp;
-		struct device_node *node;
 
-		node = priv->comp_node[comp_id];
 		comp = &priv->ddp_comp[comp_id];
-		if (!comp) {
-			dev_err(dev, "Component %pOF not initialized\n", node);
-			ret = -ENODEV;
-			return ret;
-		}
-
 		mtk_crtc->ddp_comp[i] = comp;
 
 		if (comp->funcs) {
-- 
2.17.1