From: Tzung-Bi Shih <tzungbi@google.com>
To: broonie@kernel.org, lgirdwood@gmail.com, perex@perex.cz, tiwai@suse.com
Cc: alsa-devel@alsa-project.org, tzungbi@google.com,
linux-arm-kernel@lists.infradead.org,
linux-mediatek@lists.infradead.org
Subject: [RFC PATCH] ASoC: mediatek: mt8192-mt6359: fix device_node leak
Date: Tue, 14 Dec 2021 12:00:28 +0800 [thread overview]
Message-ID: <20211214040028.2992627-1-tzungbi@google.com> (raw)
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/mt8195-mt6359-rt1019-rt5682.c#L1065
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
--
2.34.1.173.g76aa8bc2d0-goog
_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek
WARNING: multiple messages have this Message-ID (diff)
From: Tzung-Bi Shih <tzungbi@google.com>
To: broonie@kernel.org, lgirdwood@gmail.com, perex@perex.cz, tiwai@suse.com
Cc: tzungbi@google.com, alsa-devel@alsa-project.org,
linux-mediatek@lists.infradead.org,
linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH] ASoC: mediatek: mt8192-mt6359: fix device_node leak
Date: Tue, 14 Dec 2021 12:00:28 +0800 [thread overview]
Message-ID: <20211214040028.2992627-1-tzungbi@google.com> (raw)
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/mt8195-mt6359-rt1019-rt5682.c#L1065
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
--
2.34.1.173.g76aa8bc2d0-goog
WARNING: multiple messages have this Message-ID (diff)
From: Tzung-Bi Shih <tzungbi@google.com>
To: broonie@kernel.org, lgirdwood@gmail.com, perex@perex.cz, tiwai@suse.com
Cc: alsa-devel@alsa-project.org, tzungbi@google.com,
linux-arm-kernel@lists.infradead.org,
linux-mediatek@lists.infradead.org
Subject: [RFC PATCH] ASoC: mediatek: mt8192-mt6359: fix device_node leak
Date: Tue, 14 Dec 2021 12:00:28 +0800 [thread overview]
Message-ID: <20211214040028.2992627-1-tzungbi@google.com> (raw)
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/mt8195-mt6359-rt1019-rt5682.c#L1065
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
--
2.34.1.173.g76aa8bc2d0-goog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2021-12-14 4:01 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-14 4:00 Tzung-Bi Shih [this message]
2021-12-14 4:00 ` [RFC PATCH] ASoC: mediatek: mt8192-mt6359: fix device_node leak Tzung-Bi Shih
2021-12-14 4:00 ` Tzung-Bi Shih
2021-12-23 19:39 ` Mark Brown
2021-12-23 19:39 ` Mark Brown
2021-12-23 19:39 ` Mark Brown
2021-12-24 6:21 ` Tzung-Bi Shih
2021-12-24 6:21 ` Tzung-Bi Shih
2021-12-24 6:21 ` Tzung-Bi Shih
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