[PATCH] ALSA: oxygen: use helper to activate the SPDIF PCM control

[PATCH] ALSA: oxygen: use helper to activate the SPDIF PCM control

[Runyu Xiao]

oxygen_open() and oxygen_close() modify the SPDIF PCM control access
flags while holding chip->mutex. Direct access changes bypass the control
core locking and notification path.

Move the access transition outside the driver mutex and use
snd_ctl_activate_id(), which serializes the control update with the control
core.

Fixes: d0ce9946c52e ("[ALSA] add CMI8788 driver")
Assisted-by: LLM
Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn>
---
 sound/pci/oxygen/oxygen_pcm.c | 37 +++++++++++++++--------------------
 1 file changed, 16 insertions(+), 21 deletions(-)

diff --git a/sound/pci/oxygen/oxygen_pcm.c b/sound/pci/oxygen/oxygen_pcm.c
index b71635601..75efbf59a 100644
--- a/sound/pci/oxygen/oxygen_pcm.c
+++ b/sound/pci/oxygen/oxygen_pcm.c
@@ -171,16 +171,14 @@ static int oxygen_open(struct snd_pcm_substream *substream,
 	snd_pcm_set_sync(substream);
 	chip->streams[channel] = substream;
 
-	guard(mutex)(&chip->mutex);
-	chip->pcm_active |= 1 << channel;
-	if (channel == PCM_SPDIF) {
-		chip->spdif_pcm_bits = chip->spdif_bits;
-		chip->controls[CONTROL_SPDIF_PCM]->vd[0].access &=
-			~SNDRV_CTL_ELEM_ACCESS_INACTIVE;
-		snd_ctl_notify(chip->card, SNDRV_CTL_EVENT_MASK_VALUE |
-			       SNDRV_CTL_EVENT_MASK_INFO,
-			       &chip->controls[CONTROL_SPDIF_PCM]->id);
+	scoped_guard(mutex, &chip->mutex) {
+		chip->pcm_active |= 1 << channel;
+		if (channel == PCM_SPDIF)
+			chip->spdif_pcm_bits = chip->spdif_bits;
 	}
+	if (channel == PCM_SPDIF)
+		snd_ctl_activate_id(chip->card,
+				    &chip->controls[CONTROL_SPDIF_PCM]->id, 1);
 
 	return 0;
 }
@@ -220,19 +218,16 @@ static int oxygen_close(struct snd_pcm_substream *substream)
 	struct oxygen *chip = snd_pcm_substream_chip(substream);
 	unsigned int channel = oxygen_substream_channel(substream);
 
-	guard(mutex)(&chip->mutex);
-	chip->pcm_active &= ~(1 << channel);
-	if (channel == PCM_SPDIF) {
-		chip->controls[CONTROL_SPDIF_PCM]->vd[0].access |=
-			SNDRV_CTL_ELEM_ACCESS_INACTIVE;
-		snd_ctl_notify(chip->card, SNDRV_CTL_EVENT_MASK_VALUE |
-			       SNDRV_CTL_EVENT_MASK_INFO,
-			       &chip->controls[CONTROL_SPDIF_PCM]->id);
-	}
-	if (channel == PCM_SPDIF || channel == PCM_MULTICH)
-		oxygen_update_spdif_source(chip);
+	scoped_guard(mutex, &chip->mutex) {
+		chip->pcm_active &= ~(1 << channel);
+		if (channel == PCM_SPDIF || channel == PCM_MULTICH)
+			oxygen_update_spdif_source(chip);
 
-	chip->streams[channel] = NULL;
+		chip->streams[channel] = NULL;
+	}
+	if (channel == PCM_SPDIF)
+		snd_ctl_activate_id(chip->card,
+				    &chip->controls[CONTROL_SPDIF_PCM]->id, 0);
 	return 0;
 }
 
-- 
2.34.1

Re: [PATCH] ALSA: oxygen: use helper to activate the SPDIF PCM control

[Takashi Iwai]

On Sun, 27 Sep 2026 14:17:09 +0200,
Runyu Xiao wrote:
> 
> oxygen_open() and oxygen_close() modify the SPDIF PCM control access
> flags while holding chip->mutex. Direct access changes bypass the control
> core locking and notification path.
> 
> Move the access transition outside the driver mutex and use
> snd_ctl_activate_id(), which serializes the control update with the control
> core.
> 
> Fixes: d0ce9946c52e ("[ALSA] add CMI8788 driver")
> Assisted-by: LLM
> Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn>

Applied to for-next branch.  Thanks.


Takashi