[PATCH] mtd: nand: ecc-mtk: handle ECC clock enable failures

[Pengpeng Hou]

mtk_ecc_get() gets a reference to the ECC platform device, obtains the
provider state and then enables the ECC clock before initializing the
hardware.

The clk_prepare_enable() return value is currently ignored.  If enabling
the clock fails, the code still touches the ECC registers and returns a
live ECC handle to the caller.  The provider device reference acquired
by of_find_device_by_node() is also kept even though the handle setup
failed.

Propagate the clock enable error and drop the provider device reference
on that failure path.

Signed-off-by: Pengpeng Hou <pengpeng at iscas.ac.cn>
---
 drivers/mtd/nand/ecc-mtk.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/ecc-mtk.c b/drivers/mtd/nand/ecc-mtk.c
index c75bb8b80cc1..39be2e3e4ee4 100644
--- a/drivers/mtd/nand/ecc-mtk.c
+++ b/drivers/mtd/nand/ecc-mtk.c
@@ -265,6 +265,7 @@ static struct mtk_ecc *mtk_ecc_get(struct device_node *np)
 {
 	struct platform_device *pdev;
 	struct mtk_ecc *ecc;
+	int ret;
 
 	pdev = of_find_device_by_node(np);
 	if (!pdev)
@@ -276,7 +277,12 @@ static struct mtk_ecc *mtk_ecc_get(struct device_node *np)
 		return ERR_PTR(-EPROBE_DEFER);
 	}
 
-	clk_prepare_enable(ecc->clk);
+	ret = clk_prepare_enable(ecc->clk);
+	if (ret) {
+		put_device(&pdev->dev);
+		return ERR_PTR(ret);
+	}
+
 	mtk_ecc_hw_init(ecc);
 
 	return ecc;
-- 
2.50.1 (Apple Git-155)