[alsa-devel] [PATCH v2] ALSA: hda - Fix registration of beep input device

[Takashi Iwai]

The beep input device is registered via input_register_device(), but
this is called in snd_hda_attach_beep_device() where the sound devices
aren't registered yet.  This leads to the binding to non-existing
object, thus results in failure.  And, even if the binding worked
(against the PCI object), it's still racy; the input device appears
before the sound objects.

For fixing this, register the input device properly at dev_register
ops of the codec object it's bound with.  Also, call
snd_hda_detach_beep_device() at dev_disconnection so that it's
detached at the right timing.  As a bonus, since it's called in the
codec's ops, we can get rid of the further call from the other codec
drivers.

Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
v1->v2:
  Fix the error case where the device is freed without register

 sound/pci/hda/hda_beep.c       | 33 +++++++++++++++++++++++++--------
 sound/pci/hda/hda_beep.h       |  6 ++++++
 sound/pci/hda/hda_codec.c      |  8 +++++++-
 sound/pci/hda/hda_generic.c    |  1 -
 sound/pci/hda/patch_conexant.c |  4 +---
 5 files changed, 39 insertions(+), 13 deletions(-)

diff --git a/sound/pci/hda/hda_beep.c b/sound/pci/hda/hda_beep.c
index 88bb08486f77..8c6c50afc0b7 100644
--- a/sound/pci/hda/hda_beep.c
+++ b/sound/pci/hda/hda_beep.c
@@ -139,7 +139,10 @@ static void turn_off_beep(struct hda_beep *beep)
 
 static void snd_hda_do_detach(struct hda_beep *beep)
 {
-	input_unregister_device(beep->dev);
+	if (beep->registered)
+		input_unregister_device(beep->dev);
+	else
+		input_free_device(beep->dev);
 	beep->dev = NULL;
 	turn_off_beep(beep);
 }
@@ -148,7 +151,6 @@ static int snd_hda_do_attach(struct hda_beep *beep)
 {
 	struct input_dev *input_dev;
 	struct hda_codec *codec = beep->codec;
-	int err;
 
 	input_dev = input_allocate_device();
 	if (!input_dev)
@@ -169,12 +171,6 @@ static int snd_hda_do_attach(struct hda_beep *beep)
 	input_dev->dev.parent = &codec->dev;
 	input_set_drvdata(input_dev, beep);
 
-	err = input_register_device(input_dev);
-	if (err < 0) {
-		input_free_device(input_dev);
-		codec_err(codec, "hda_beep: unable to register input device\n");
-		return err;
-	}
 	beep->dev = input_dev;
 	return 0;
 }
@@ -244,6 +240,27 @@ void snd_hda_detach_beep_device(struct hda_codec *codec)
 }
 EXPORT_SYMBOL_GPL(snd_hda_detach_beep_device);
 
+int snd_hda_register_beep_device(struct hda_codec *codec)
+{
+	struct hda_beep *beep = codec->beep;
+	int err;
+
+	if (!beep || !beep->dev)
+		return 0;
+
+	err = input_register_device(beep->dev);
+	if (err < 0) {
+		codec_err(codec, "hda_beep: unable to register input device\n");
+		input_free_device(beep->dev);
+		codec->beep = NULL;
+		kfree(beep);
+		return err;
+	}
+	beep->registered = true;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_hda_register_beep_device);
+
 static bool ctl_has_mute(struct snd_kcontrol *kcontrol)
 {
 	struct hda_codec *codec = snd_kcontrol_chip(kcontrol);
diff --git a/sound/pci/hda/hda_beep.h b/sound/pci/hda/hda_beep.h
index cb88464676b6..a63b5e077332 100644
--- a/sound/pci/hda/hda_beep.h
+++ b/sound/pci/hda/hda_beep.h
@@ -34,6 +34,7 @@ struct hda_beep {
 	char phys[32];
 	int tone;
 	hda_nid_t nid;
+	unsigned int registered:1;
 	unsigned int enabled:1;
 	unsigned int linear_tone:1;	/* linear tone for IDT/STAC codec */
 	unsigned int playing:1;
@@ -45,6 +46,7 @@ struct hda_beep {
 int snd_hda_enable_beep_device(struct hda_codec *codec, int enable);
 int snd_hda_attach_beep_device(struct hda_codec *codec, int nid);
 void snd_hda_detach_beep_device(struct hda_codec *codec);
+int snd_hda_register_beep_device(struct hda_codec *codec);
 #else
 static inline int snd_hda_attach_beep_device(struct hda_codec *codec, int nid)
 {
@@ -53,5 +55,9 @@ static inline int snd_hda_attach_beep_device(struct hda_codec *codec, int nid)
 static inline void snd_hda_detach_beep_device(struct hda_codec *codec)
 {
 }
+static inline int snd_hda_register_beep_device(struct hda_codec *codec)
+{
+	return 0;
+}
 #endif
 #endif
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 6db2dbcbf4d3..4c20277a6835 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -1379,14 +1379,19 @@ static unsigned int hda_set_power_state(struct hda_codec *codec,
 static int snd_hda_codec_dev_register(struct snd_device *device)
 {
 	struct hda_codec *codec = device->device_data;
+	int err = device_add(&codec->dev);
 
-	return device_add(&codec->dev);
+	if (err < 0)
+		return err;
+	snd_hda_register_beep_device(codec);
+	return 0;
 }
 
 static int snd_hda_codec_dev_disconnect(struct snd_device *device)
 {
 	struct hda_codec *codec = device->device_data;
 
+	snd_hda_detach_beep_device(codec);
 	device_del(&codec->dev);
 	return 0;
 }
@@ -2692,6 +2697,7 @@ int snd_hda_codec_reset(struct hda_codec *codec)
 				  bus->pcm_dev_bits);
 		}
 	}
+	snd_hda_detach_beep_device(codec);
 	if (codec->patch_ops.free)
 		codec->patch_ops.free(codec);
 	memset(&codec->patch_ops, 0, sizeof(codec->patch_ops));
diff --git a/sound/pci/hda/hda_generic.c b/sound/pci/hda/hda_generic.c
index 9e0609a4b2ba..16133881e967 100644
--- a/sound/pci/hda/hda_generic.c
+++ b/sound/pci/hda/hda_generic.c
@@ -5350,7 +5350,6 @@ EXPORT_SYMBOL_GPL(snd_hda_gen_init);
 void snd_hda_gen_free(struct hda_codec *codec)
 {
 	snd_hda_apply_fixup(codec, HDA_FIXUP_ACT_FREE);
-	snd_hda_detach_beep_device(codec);
 	snd_hda_gen_spec_free(codec->spec);
 	kfree(codec->spec);
 	codec->spec = NULL;
diff --git a/sound/pci/hda/patch_conexant.c b/sound/pci/hda/patch_conexant.c
index 09d6d0db2b06..1dc7e974f3b1 100644
--- a/sound/pci/hda/patch_conexant.c
+++ b/sound/pci/hda/patch_conexant.c
@@ -445,9 +445,7 @@ static int conexant_init(struct hda_codec *codec)
 
 static void conexant_free(struct hda_codec *codec)
 {
-	struct conexant_spec *spec = codec->spec;
-	snd_hda_detach_beep_device(codec);
-	kfree(spec);
+	kfree(codec->spec);
 }
 
 static const struct snd_kcontrol_new cxt_capture_mixers[] = {
-- 
1.9.0