[alsa-devel] [PATCH 2/4] ALSA: hda: Add codec on bus address table lately

[Takashi Iwai]

The call of snd_hdac_bus_add_device() is needed only for registering
the codec onto the bus caddr_tbl[] that is referred essentially only
in the unsol event handler.  That is, the reason of this call and the
release by the counter-part function snd_hdac_bus_remove_device() is
just to assure that the unsol event gets notified to the codec.

But the current implementation of the unsol notification wouldn't work
properly when the codec is still in a premature init state.  So this
patch tries to work around it by delaying the caddr_tbl[] registration
at the point of snd_hdac_device_register().

Also, the order of snd_hdac_bus_remove_device() and device_del() calls
are shuffled to make sure that the unsol event is masked before
deleting the device.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=204565
Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/hda/hdac_device.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/sound/hda/hdac_device.c b/sound/hda/hdac_device.c
index b26cc93e7e10..033bcef8751a 100644
--- a/sound/hda/hdac_device.c
+++ b/sound/hda/hdac_device.c
@@ -61,10 +61,6 @@ int snd_hdac_device_init(struct hdac_device *codec, struct hdac_bus *bus,
 	pm_runtime_get_noresume(&codec->dev);
 	atomic_set(&codec->in_pm, 0);
 
-	err = snd_hdac_bus_add_device(bus, codec);
-	if (err < 0)
-		goto error;
-
 	/* fill parameters */
 	codec->vendor_id = snd_hdac_read_parm(codec, AC_NODE_ROOT,
 					      AC_PAR_VENDOR_ID);
@@ -143,15 +139,22 @@ int snd_hdac_device_register(struct hdac_device *codec)
 	err = device_add(&codec->dev);
 	if (err < 0)
 		return err;
+	err = snd_hdac_bus_add_device(codec->bus, codec);
+	if (err < 0)
+		goto error;
 	mutex_lock(&codec->widget_lock);
 	err = hda_widget_sysfs_init(codec);
 	mutex_unlock(&codec->widget_lock);
-	if (err < 0) {
-		device_del(&codec->dev);
-		return err;
-	}
+	if (err < 0)
+		goto error_remove;
 
 	return 0;
+
+ error_remove:
+	snd_hdac_bus_remove_device(codec->bus, codec);
+ error:
+	device_del(&codec->dev);
+	return err;
 }
 EXPORT_SYMBOL_GPL(snd_hdac_device_register);
 
@@ -165,8 +168,8 @@ void snd_hdac_device_unregister(struct hdac_device *codec)
 		mutex_lock(&codec->widget_lock);
 		hda_widget_sysfs_exit(codec);
 		mutex_unlock(&codec->widget_lock);
-		device_del(&codec->dev);
 		snd_hdac_bus_remove_device(codec->bus, codec);
+		device_del(&codec->dev);
 	}
 }
 EXPORT_SYMBOL_GPL(snd_hdac_device_unregister);
-- 
2.16.4