[PATCH] ASoC: hdac_hdmi: Fix resource cleanup on probe failure

[Haoxiang Li]

hdac_hdmi_dev_probe() gets the HDA link before allocating and
initializing the HDMI codec private data. Several later error
paths return directly without dropping the link reference,
leaving the hlink refcount unbalanced.

Release the link reference on probe failures. Also turn display
power off if the failure happens after it has been enabled.

This issue was dicussed in:
https://lore.kernel.org/all/s5h1s0esk8o.wl-tiwai@xxxxxxx/
I think the paths fixed here are probe failure paths: the device
has not been fully initialized or bound, and runtime PM suspend
cannot be relied on to balance the reference taken during probe.

Signed-off-by: Haoxiang Li <haoxiang_li2024@xxxxxxx>
---
 sound/soc/codecs/hdac_hdmi.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/sound/soc/codecs/hdac_hdmi.c b/sound/soc/codecs/hdac_hdmi.c
index 3220f9226e0b..38073a70fa61 100644
--- a/sound/soc/codecs/hdac_hdmi.c
+++ b/sound/soc/codecs/hdac_hdmi.c
@@ -1866,8 +1866,10 @@ static int hdac_hdmi_dev_probe(struct hdac_device *hdev)
 	snd_hdac_ext_bus_link_get(hdev->bus, hlink);
 
 	hdmi_priv = devm_kzalloc(&hdev->dev, sizeof(*hdmi_priv), GFP_KERNEL);
-	if (hdmi_priv == NULL)
+	if (hdmi_priv == NULL) {
+		snd_hdac_ext_bus_link_put(hdev->bus, hlink);
 		return -ENOMEM;
+	}
 
 	snd_hdac_register_chmap_ops(hdev, &hdmi_priv->chmap);
 	hdmi_priv->chmap.ops.get_chmap = hdac_hdmi_get_chmap;
@@ -1876,8 +1878,10 @@ static int hdac_hdmi_dev_probe(struct hdac_device *hdev)
 	hdmi_priv->chmap.ops.get_spk_alloc = hdac_hdmi_get_spk_alloc;
 	hdmi_priv->hdev = hdev;
 
-	if (!hdac_id)
+	if (!hdac_id) {
+		snd_hdac_ext_bus_link_put(hdev->bus, hlink);
 		return -ENODEV;
+	}
 
 	if (hdac_id->driver_data)
 		hdmi_priv->drv_data =
@@ -1902,6 +1906,8 @@ static int hdac_hdmi_dev_probe(struct hdac_device *hdev)
 	if (ret < 0) {
 		dev_err(&hdev->dev,
 			"Failed in parse and map nid with err: %d\n", ret);
+		snd_hdac_ext_bus_link_put(hdev->bus, hlink);
+		snd_hdac_display_power(hdev->bus, hdev->addr, false);
 		return ret;
 	}
 	snd_hdac_refresh_widgets(hdev);
-- 
2.25.1