[alsa-devel] [PATCH] ASoC: kirkwood: fix device remove ordering

[Russell King]

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 at armlinux.org.uk>
---
 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 c323ae314b55..eb38cdb37f0e 100644
--- a/sound/soc/kirkwood/kirkwood-i2s.c
+++ b/sound/soc/kirkwood/kirkwood-i2s.c
@@ -591,7 +591,7 @@ 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");
@@ -614,6 +614,7 @@ 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