Make sure to drop the reference taken when looking up the VPU firmware
device during codec init on probe failure (e.g. probe deferral) and on
driver unbind.

Fixes: 590577a4e525 ("[media] vcodec: mediatek: Add Mediatek V4L2 Video Decoder Driver")
Fixes: 4e855a6efa54 ("[media] vcodec: mediatek: Add Mediatek V4L2 Video Encoder Driver")
Cc: stable@vger.kernel.org	# 4.8
Cc: Tiffany Lin <tiffany.lin@mediatek.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 .../mediatek/vcodec/common/mtk_vcodec_fw_vpu.c      | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c b/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c
index d7027d600208..9237738d7632 100644
--- a/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c
+++ b/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c
@@ -83,12 +83,20 @@ static const struct mtk_vcodec_fw_ops mtk_vcodec_vpu_msg = {
 	.release = mtk_vcodec_vpu_release,
 };
 
+static void mtk_vcodec_vpu_put_device(void *_dev)
+{
+	struct device *dev = _dev;
+
+	put_device(dev);
+}
+
 struct mtk_vcodec_fw *mtk_vcodec_fw_vpu_init(void *priv, enum mtk_vcodec_fw_use fw_use)
 {
 	struct platform_device *fw_pdev;
 	struct platform_device *plat_dev;
 	struct mtk_vcodec_fw *fw;
 	enum rst_id rst_id;
+	int ret;
 
 	if (fw_use == ENCODER) {
 		struct mtk_vcodec_enc_dev *enc_dev = priv;
@@ -111,6 +119,11 @@ struct mtk_vcodec_fw *mtk_vcodec_fw_vpu_init(void *priv, enum mtk_vcodec_fw_use
 		return ERR_PTR(-EINVAL);
 	}
 
+	ret = devm_add_action_or_reset(&plat_dev->dev, mtk_vcodec_vpu_put_device,
+				       &fw_pdev->dev);
+	if (ret)
+		return ERR_PTR(ret);
+
 	if (fw_use == DECODER)
 		vpu_wdt_reg_handler(fw_pdev, mtk_vcodec_vpu_reset_dec_handler, priv, rst_id);
 	else
-- 
2.49.1