[PATCH v2 3/5] ALSA: hda: Add lock around codec->registered flag manipulations

[Takashi Iwai]

Currently the places setting or clearing codec->registered flag have
no locking, while its reference in the unsol handling work
snd_hdac_bus_process_unsol_events() takes the bus->reg_lock lock.
Let's add the same bus->reg_lock at the places where codec->registered
is set and cleared for avoiding the races.

Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
v1->v2: fix build error

 sound/hda/common/codec.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/sound/hda/common/codec.c b/sound/hda/common/codec.c
index 94da4f3a21ed..18838a45e6f7 100644
--- a/sound/hda/common/codec.c
+++ b/sound/hda/common/codec.c
@@ -757,11 +757,15 @@ static void codec_release_pcms(struct hda_codec *codec)
  */
 void snd_hda_codec_cleanup_for_unbind(struct hda_codec *codec)
 {
+	struct hda_bus *bus = codec->bus;
+
 	if (codec->core.registered) {
 		/* pm_runtime_put() is called in snd_hdac_device_exit() */
 		pm_runtime_get_noresume(hda_codec_dev(codec));
 		pm_runtime_disable(hda_codec_dev(codec));
+		spin_lock_irq(&bus->core.reg_lock);
 		codec->core.registered = false;
+		spin_unlock_irq(&bus->core.reg_lock);
 	}
 
 	snd_hda_codec_disconnect_pcms(codec);
@@ -808,6 +812,8 @@ void snd_hda_codec_display_power(struct hda_codec *codec, bool enable)
  */
 void snd_hda_codec_register(struct hda_codec *codec)
 {
+	struct hda_bus *bus = codec->bus;
+
 	if (codec->core.registered)
 		return;
 	if (device_is_registered(hda_codec_dev(codec))) {
@@ -815,7 +821,9 @@ void snd_hda_codec_register(struct hda_codec *codec)
 		pm_runtime_enable(hda_codec_dev(codec));
 		/* it was powered up in snd_hda_codec_new(), now all done */
 		snd_hda_power_down(codec);
+		spin_lock_irq(&bus->core.reg_lock);
 		codec->core.registered = true;
+		spin_unlock_irq(&bus->core.reg_lock);
 	}
 }
 EXPORT_SYMBOL_GPL(snd_hda_codec_register);
-- 
2.55.0