[PATCH 4/5] drm/mediatek: mtk_hdmi: fix probe device leaks

[Johan Hovold <johan@kernel.org>]

Make sure to drop the references to the DDC adapter and CEC device
taken during probe on probe failure (e.g. probe deferral) and on driver
unbind.

Fixes: 8f83f26891e1 ("drm/mediatek: Add HDMI support")
Cc: stable@vger.kernel.org	# 4.8
Cc: Jie Qiu <jie.qiu@mediatek.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/gpu/drm/mediatek/mtk_hdmi.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c
index b766dd5e6c8d..306e2c907311 100644
--- a/drivers/gpu/drm/mediatek/mtk_hdmi.c
+++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c
@@ -1345,6 +1345,13 @@ static const struct drm_bridge_funcs mtk_hdmi_bridge_funcs = {
 	.edid_read = mtk_hdmi_bridge_edid_read,
 };
 
+static void mtk_hdmi_put_device(void *_dev)
+{
+	struct device *dev = _dev;
+
+	put_device(dev);
+}
+
 static int mtk_hdmi_get_cec_dev(struct mtk_hdmi *hdmi, struct device *dev, struct device_node *np)
 {
 	struct platform_device *cec_pdev;
@@ -1369,6 +1376,10 @@ static int mtk_hdmi_get_cec_dev(struct mtk_hdmi *hdmi, struct device *dev, struc
 	}
 	of_node_put(cec_np);
 
+	ret = devm_add_action_or_reset(dev, mtk_hdmi_put_device, &cec_pdev->dev);
+	if (ret)
+		return ret;
+
 	/*
 	 * The mediatek,syscon-hdmi property contains a phandle link to the
 	 * MMSYS_CONFIG device and the register offset of the HDMI_SYS_CFG
@@ -1423,6 +1434,10 @@ static int mtk_hdmi_dt_parse_pdata(struct mtk_hdmi *hdmi,
 	if (!hdmi->ddc_adpt)
 		return dev_err_probe(dev, -EINVAL, "Failed to get ddc i2c adapter by node\n");
 
+	ret = devm_add_action_or_reset(dev, mtk_hdmi_put_device, &hdmi->ddc_adpt->dev);
+	if (ret)
+		return ret;
+
 	ret = mtk_hdmi_get_cec_dev(hdmi, dev, np);
 	if (ret)
 		return ret;
-- 
2.49.1