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@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20191101170635.26389-1-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/codecs/hdac_hda.c b/sound/soc/codecs/hdac_hda.c
index 91242b6f8ea7adf27e05f2883397f932a2f1688e..4570f662fb48b4090979be99b13087c3c0507a62 100644 (file)
--- 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[] = {