[PATCH 3/9] ALSA: hda: Make device usage_count consistent across subsequent probing

[Cezary Rojewski]

AVS HDAudio bus driver does not tie with codec drivers tighly and
snd_hda_codec_device_new() can be called after codec's module reload. In
such case, rpm is forbidden and invoking pm_runtime_forbid()
unconditionally causes device's usage_count to become unbalanced. This
is later caught by WARN_ON() found in sound/soc/hda.c. Detect such
circumstance and bump the usage_count instead.

Signed-off-by: Cezary Rojewski <cezary.rojewski at intel.com>
---
 sound/pci/hda/hda_codec.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 9ceb642ac819..83d954ab056f 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -1044,8 +1044,14 @@ int snd_hda_codec_device_new(struct hda_bus *bus, struct snd_card *card,
 			goto error;
 	}
 
+#ifdef CONFIG_PM
 	/* PM runtime needs to be enabled later after binding codec */
-	pm_runtime_forbid(&codec->core.dev);
+	if (codec->core.dev.power.runtime_auto)
+		pm_runtime_forbid(&codec->core.dev);
+	else
+		/* Keep the usage_count consistent across subsequent probing */
+		pm_runtime_get_noresume(&codec->core.dev);
+#endif
 
 	return 0;
 
-- 
2.25.1