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From:   Miaoqian Lin <linmq006@gmail.com>
To:     Thierry Reding <thierry.reding@gmail.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Jonathan Hunter <jonathanh@nvidia.com>,
        Mark Zhang <markz@nvidia.com>,
        Terje Bergstrom <tbergstrom@nvidia.com>,
        Dave Airlie <airlied@redhat.com>,
        dri-devel@lists.freedesktop.org, linux-tegra@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     linmq006@gmail.com
Subject: [PATCH v2] drm/tegra: dc: rgb: Fix refcount leak in tegra_dc_rgb_probe
Date:   Fri,  3 Jun 2022 17:27:03 +0400
Message-Id: <20220603132703.42085-1-linmq006@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

of_get_child_by_name() returns a node pointer with refcount
incremented, we should use of_node_put() on it when not need anymore.
So add of_node_put() in error paths.

Fixes: d8f4a9eda006 ("drm: Add NVIDIA Tegra20 support")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
changes in v2:
- update Fixes tag.
v1 Link: https://lore.kernel.org/r/20220602155615.43277-1-linmq006@gmail.com
---
 drivers/gpu/drm/tegra/rgb.c | 31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/tegra/rgb.c b/drivers/gpu/drm/tegra/rgb.c
index ff8fce36d2aa..cef2b1b72385 100644
--- a/drivers/gpu/drm/tegra/rgb.c
+++ b/drivers/gpu/drm/tegra/rgb.c
@@ -196,12 +196,16 @@ int tegra_dc_rgb_probe(struct tegra_dc *dc)
 	int err;
 
 	np = of_get_child_by_name(dc->dev->of_node, "rgb");
-	if (!np || !of_device_is_available(np))
-		return -ENODEV;
+	if (!np || !of_device_is_available(np)) {
+		err = -ENODEV;
+		goto err_put_node;
+	}
 
 	rgb = devm_kzalloc(dc->dev, sizeof(*rgb), GFP_KERNEL);
-	if (!rgb)
-		return -ENOMEM;
+	if (!rgb) {
+		err = -ENOMEM;
+		goto err_put_node;
+	}
 
 	rgb->output.dev = dc->dev;
 	rgb->output.of_node = np;
@@ -209,31 +213,34 @@ int tegra_dc_rgb_probe(struct tegra_dc *dc)
 
 	err = tegra_output_probe(&rgb->output);
 	if (err < 0)
-		return err;
+		goto err_put_node;
+
 
 	rgb->clk = devm_clk_get(dc->dev, NULL);
 	if (IS_ERR(rgb->clk)) {
 		dev_err(dc->dev, "failed to get clock\n");
-		return PTR_ERR(rgb->clk);
+		err =  PTR_ERR(rgb->clk);
+		goto err_put_node;
 	}
 
 	rgb->clk_parent = devm_clk_get(dc->dev, "parent");
 	if (IS_ERR(rgb->clk_parent)) {
 		dev_err(dc->dev, "failed to get parent clock\n");
-		return PTR_ERR(rgb->clk_parent);
+		err = PTR_ERR(rgb->clk_parent);
+		goto err_put_node;
 	}
 
 	err = clk_set_parent(rgb->clk, rgb->clk_parent);
 	if (err < 0) {
 		dev_err(dc->dev, "failed to set parent clock: %d\n", err);
-		return err;
+		goto err_put_node;
 	}
 
 	rgb->pll_d_out0 = clk_get_sys(NULL, "pll_d_out0");
 	if (IS_ERR(rgb->pll_d_out0)) {
 		err = PTR_ERR(rgb->pll_d_out0);
 		dev_err(dc->dev, "failed to get pll_d_out0: %d\n", err);
-		return err;
+		goto err_put_node;
 	}
 
 	if (dc->soc->has_pll_d2_out0) {
@@ -241,13 +248,17 @@ int tegra_dc_rgb_probe(struct tegra_dc *dc)
 		if (IS_ERR(rgb->pll_d2_out0)) {
 			err = PTR_ERR(rgb->pll_d2_out0);
 			dev_err(dc->dev, "failed to get pll_d2_out0: %d\n", err);
-			return err;
+			goto err_put_node;
 		}
 	}
 
 	dc->rgb = &rgb->output;
 
 	return 0;
+
+err_put_node:
+	of_node_put(np);
+	return err;
 }
 
 int tegra_dc_rgb_remove(struct tegra_dc *dc)
-- 
2.25.1