The of_parse_phandle() document: >>> Use of_node_put() on it when done.

The driver didn't call of_node_put(). Fixes the leak.

Signed-off-by: Tzung-Bi Shih tzungbi@google.com --- Hi maintainers,

Need your comments. The patch is one of the partial fixes that I think it makes the most sense.

Option 1. Machine driver makes sure the object is valid until registered

This patch adopts the option. It needs snd_soc_register_card() to call of_node_get() somewhere to hold the reference count of of_node. However, I failed to find similar logic in soc-core.c.

Option 2. Machine driver borrows the reference count

This is what [1] adopts. Decreasing the reference count in device's remove() to make sure the object is valid for whole sound card's lifecycle.

[1]: https://elixir.bootlin.com/linux/v5.16-rc5/source/sound/soc/mediatek/mt8195/...

In fact, in my test environment, CONFIG_OF_DYNAMIC is not set. The implementation is empty[2].

Per [3]: >>> Hardly any platforms need this

[2]: https://elixir.bootlin.com/linux/v5.16-rc5/source/include/linux/of.h#L125 [3]: https://elixir.bootlin.com/linux/v5.16-rc5/source/drivers/of/Kconfig#L55

I am not sure if it is worthy to find somewhere to hold the reference count in soc-core.c but I think option 1 makes it more clear to drivers.

sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c b/sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c index a606133951b7..24a5d0adec1b 100644 --- a/sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c +++ b/sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c @@ -1172,7 +1172,11 @@ static int mt8192_mt6359_dev_probe(struct platform_device *pdev) return ret; }

- return devm_snd_soc_register_card(&pdev->dev, card); + ret = devm_snd_soc_register_card(&pdev->dev, card); + + of_node_put(platform_node); + of_node_put(hdmi_codec); + return ret; }

#ifdef CONFIG_OF