[alsa-devel] Applied "ASoC: hdac_hda: fix race in device removal" to the asoc tree

[Mark Brown]

The patch

   ASoC: hdac_hda: fix race in device removal

has been applied to the asoc tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-5.4

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 5dc7d5bc9627eb26d33c7c7eefc467cf217f9326 Mon Sep 17 00:00:00 2001
From: Kai Vehmanen <kai.vehmanen at linux.intel.com>
Date: Fri, 1 Nov 2019 12:06:35 -0500
Subject: [PATCH] ASoC: hdac_hda: fix race in device removal

When ASoC card instance is removed containing a HDA codec,
hdac_hda_codec_remove() may run in parallel with codec resume.
This will cause problems if the HDA link is freed with
snd_hdac_ext_bus_link_put() while the codec is still in
middle of its resume process.

To fix this, change the order such that pm_runtime_disable()
is called before the link is freed. This will ensure any
pending runtime PM action is completed before proceeding
to free the link.

This issue can be easily hit with e.g. SOF driver by loading and
unloading the drivers.

Signed-off-by: Kai Vehmanen <kai.vehmanen at linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
Link: https://lore.kernel.org/r/20191101170635.26389-1-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie at kernel.org>
---
 sound/soc/codecs/hdac_hda.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/soc/codecs/hdac_hda.c b/sound/soc/codecs/hdac_hda.c
index 91242b6f8ea7..4570f662fb48 100644
--- a/sound/soc/codecs/hdac_hda.c
+++ b/sound/soc/codecs/hdac_hda.c
@@ -410,8 +410,8 @@ static void hdac_hda_codec_remove(struct snd_soc_component *component)
 		return;
 	}
 
-	snd_hdac_ext_bus_link_put(hdev->bus, hlink);
 	pm_runtime_disable(&hdev->dev);
+	snd_hdac_ext_bus_link_put(hdev->bus, hlink);
 }
 
 static const struct snd_soc_dapm_route hdac_hda_dapm_routes[] = {
-- 
2.20.1