[PATCH] remoteproc: scp: fix device reference leak on failed lookup

[Johan Hovold <johan@kernel.org>]

Make sure to drop the reference taken to the SCP device when attempting
to look up its driver data before the driver has been bound.

Note that holding a reference to a device does not prevent its driver
data from going away.

Fixes: 63c13d61eafe ("remoteproc/mediatek: add SCP support for mt8183")
Cc: stable@vger.kernel.org	# 5.6
Cc: Erin Lo <erin.lo@mediatek.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/remoteproc/mtk_scp.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
index 85a74c9ec521..436656bdfa8b 100644
--- a/drivers/remoteproc/mtk_scp.c
+++ b/drivers/remoteproc/mtk_scp.c
@@ -36,6 +36,7 @@ struct mtk_scp *scp_get(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct device_node *scp_node;
 	struct platform_device *scp_pdev;
+	struct mtk_scp *scp;
 
 	scp_node = of_parse_phandle(dev->of_node, "mediatek,scp", 0);
 	if (!scp_node) {
@@ -51,7 +52,13 @@ struct mtk_scp *scp_get(struct platform_device *pdev)
 		return NULL;
 	}
 
-	return platform_get_drvdata(scp_pdev);
+	scp = platform_get_drvdata(scp_pdev);
+	if (!scp) {
+		put_device(&scp_pdev->dev);
+		return NULL;
+	}
+
+	return scp;
 }
 EXPORT_SYMBOL_GPL(scp_get);
 
-- 
2.54.0