linux-kernel - [PATCH review for 4.9 21/50] drm/fsl-dcu: check for clk_prepare

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Date:   Sat, 7 Oct 2017 22:36:51 +0000
From:   "Levin, Alexander (Sasha Levin)" <alexander.levin@...izon.com>
To:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "stable@...r.kernel.org" <stable@...r.kernel.org>
Cc:     Fabio Estevam <fabio.estevam@....com>,
        Stefan Agner <stefan@...er.ch>,
        "Levin, Alexander (Sasha Levin)" <alexander.levin@...izon.com>
Subject: [PATCH review for 4.9 21/50] drm/fsl-dcu: check for
 clk_prepare_enable() error

From: Fabio Estevam <fabio.estevam@....com>

[ Upstream commit ef15d36154cc741d7ded4ae4fa0cf7987354e313 ]

clk_prepare_enable() may fail, so we should better check its return
value.

Also place the of_node_put() function right after clk_prepare_enable(),
in order to avoid calling of_node_put() twice in case clk_prepare_enable()
fails.

Signed-off-by: Fabio Estevam <fabio.estevam@....com>
Signed-off-by: Stefan Agner <stefan@...er.ch>
Signed-off-by: Sasha Levin <alexander.levin@...izon.com>
---
 drivers/gpu/drm/fsl-dcu/fsl_tcon.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/fsl-dcu/fsl_tcon.c b/drivers/gpu/drm/fsl-dcu/fsl_tcon.c
index 3194e544ee27..faacc813254c 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_tcon.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_tcon.c
@@ -89,9 +89,13 @@ struct fsl_tcon *fsl_tcon_init(struct device *dev)
 		goto err_node_put;
 	}
 
-	of_node_put(np);
-	clk_prepare_enable(tcon->ipg_clk);
+	ret = clk_prepare_enable(tcon->ipg_clk);
+	if (ret) {
+		dev_err(dev, "Couldn't enable the TCON clock\n");
+		goto err_node_put;
+	}
 
+	of_node_put(np);
 	dev_info(dev, "Using TCON in bypass mode\n");
 
 	return tcon;
-- 
2.11.0