[PATCH 4.19 008/321] ASoC: kirkwood: fix device remove ordering

Greg Kroah-Hartman
2019-12-03T22:47:06Z

From: Russell King <rmk+kernel@armlinux.org.uk>

[ Upstream commit dc39596a906d5b604f4e64597b6e904fc14625e8 ]

The devm conversion of kirkwood was incorrect; on removal, devm takes
effect after the "remove" function has returned. So, the effect of
the conversion was to change the order during remove from:

- snd_soc_unregister_component() (unpublishes interfaces)
- clk_disable_unprepare()
- cleanup resources

After the conversion, this became:

- clk_disable_unprepare() - while the device may still be active
- snd_soc_unregister_component()
- cleanup resources

Hence, it introduces a bug, where the internal clock for the device
may be shut down before the device itself has been shut down. It is
known that Marvell SoCs, including Dove, locks up if registers for a
peripheral that has its clocks disabled are accessed.

Fixes: f98fc0f8154e ("ASoC: kirkwood: replace platform to component")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/E1iNGyP-0004oN-BA@rmk-PC.armlinux.org.uk
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/soc/kirkwood/kirkwood-i2s.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sound/soc/kirkwood/kirkwood-i2s.c b/sound/soc/kirkwood/kirkwood-i2s.c
index b84a504168473..4395bb7029a06 100644
--- a/sound/soc/kirkwood/kirkwood-i2s.c
+++ b/sound/soc/kirkwood/kirkwood-i2s.c
@@ -595,7 +595,7 @@ static int kirkwood_i2s_dev_probe(struct platform_device *pdev)
priv->ctl_rec |= KIRKWOOD_RECCTL_BURST_128;
}

- err = devm_snd_soc_register_component(&pdev->dev, &kirkwood_soc_component,
+ err = snd_soc_register_component(&pdev->dev, &kirkwood_soc_component,
soc_dai, 2);
if (err) {
dev_err(&pdev->dev, "snd_soc_register_component failed\n");
@@ -618,6 +618,7 @@ static int kirkwood_i2s_dev_remove(struct platform_device *pdev)
{
struct kirkwood_dma_data *priv = dev_get_drvdata(&pdev->dev);

+ snd_soc_unregister_component(&pdev->dev);
if (!IS_ERR(priv->extclk))
clk_disable_unprepare(priv->extclk);
clk_disable_unprepare(priv->clk);
--
2.20.1