ctxfi stores the Line Capture Switch and Mic Capture Switch controls in
a file-scope kctls[] array so do_line_mic_switch() can notify the
opposite control when the shared line/mic input selection changes.

That storage is shared by all ctxfi cards. If more than one X-Fi card is
present, a later card can overwrite the pointers saved by an earlier one.
A control update on one card can then use another card's kcontrol object
for snd_ctl_notify(). If that other card is removed, the saved pointer can
also become stale.

Store those notification targets in struct ct_mixer instead. The mixer is
per-card state and matches the lifetime of the controls created for that
card.

Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com>
---
 sound/pci/ctxfi/ctmixer.c | 17 +++++++----------
 sound/pci/ctxfi/ctmixer.h |  3 +++
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/sound/pci/ctxfi/ctmixer.c b/sound/pci/ctxfi/ctmixer.c
index 50ab69aca2fa..9abe1d53c3c5 100644
--- a/sound/pci/ctxfi/ctmixer.c
+++ b/sound/pci/ctxfi/ctmixer.c
@@ -221,10 +221,6 @@ ct_mixer_recording_select(struct ct_mixer *mixer, enum CT_AMIXER_CTL type);
 static void
 ct_mixer_recording_unselect(struct ct_mixer *mixer, enum CT_AMIXER_CTL type);
 
-/* FIXME: this static looks like it would fail if more than one card was */
-/* installed. */
-static struct snd_kcontrol *kctls[2] = {NULL};
-
 static enum CT_AMIXER_CTL get_amixer_index(enum CTALSA_MIXER_CTL alsa_index)
 {
 	switch (alsa_index) {
@@ -481,17 +477,18 @@ static struct snd_kcontrol_new mic_source_ctl = {
 static void
 do_line_mic_switch(struct ct_atc *atc, enum CTALSA_MIXER_CTL type)
 {
+	struct ct_mixer *mixer = atc->mixer;
 
 	if (MIXER_LINEIN_C_S == type) {
 		atc->select_line_in(atc);
-		set_switch_state(atc->mixer, MIXER_MIC_C_S, 0);
+		set_switch_state(mixer, MIXER_MIC_C_S, 0);
 		snd_ctl_notify(atc->card, SNDRV_CTL_EVENT_MASK_VALUE,
-							&kctls[1]->id);
+			       &mixer->line_mic_kctls[1]->id);
 	} else if (MIXER_MIC_C_S == type) {
 		atc->select_mic_in(atc);
-		set_switch_state(atc->mixer, MIXER_LINEIN_C_S, 0);
+		set_switch_state(mixer, MIXER_LINEIN_C_S, 0);
 		snd_ctl_notify(atc->card, SNDRV_CTL_EVENT_MASK_VALUE,
-							&kctls[0]->id);
+			       &mixer->line_mic_kctls[0]->id);
 	}
 }
 
@@ -778,9 +775,9 @@ ct_mixer_kcontrol_new(struct ct_mixer *mixer, struct snd_kcontrol_new *new)
 
 	switch (new->private_value) {
 	case MIXER_LINEIN_C_S:
-		kctls[0] = kctl; break;
+		mixer->line_mic_kctls[0] = kctl; break;
 	case MIXER_MIC_C_S:
-		kctls[1] = kctl; break;
+		mixer->line_mic_kctls[1] = kctl; break;
 	default:
 		break;
 	}
diff --git a/sound/pci/ctxfi/ctmixer.h b/sound/pci/ctxfi/ctmixer.h
index dd23d227aeb5..0c0963bba99c 100644
--- a/sound/pci/ctxfi/ctmixer.h
+++ b/sound/pci/ctxfi/ctmixer.h
@@ -17,6 +17,8 @@
 #include "ctatc.h"
 #include "ctresource.h"
 
+struct snd_kcontrol;
+
 #define INIT_VOL	0x1c00
 
 enum MIXER_PORT_T {
@@ -42,6 +44,7 @@ struct ct_mixer {
 	struct ct_atc *atc;
 
 	struct sum **sums;		/* sum resources for signal collection */
+	struct snd_kcontrol *line_mic_kctls[2]; /* line/mic capture switch controls */
 	unsigned int switch_state; /* A bit-map to indicate state of switches */
 
 	int (*get_output_ports)(struct ct_mixer *mixer, enum MIXER_PORT_T type,

---
base-commit: 910e9f1bc3bc96e6d067c405ba30d69c4feff46e
change-id: 20260428-alsa-ctxfi-mixer-kctls-f0b7d1ad178f

Best regards,
--  
Cássio Gabriel <cassiogabrielcontato@gmail.com>

On Mon, 18 May 2026 04:33:49 +0200,
Cássio Gabriel wrote:
> 
> ctxfi stores the Line Capture Switch and Mic Capture Switch controls in
> a file-scope kctls[] array so do_line_mic_switch() can notify the
> opposite control when the shared line/mic input selection changes.
> 
> That storage is shared by all ctxfi cards. If more than one X-Fi card is
> present, a later card can overwrite the pointers saved by an earlier one.
> A control update on one card can then use another card's kcontrol object
> for snd_ctl_notify(). If that other card is removed, the saved pointer can
> also become stale.
> 
> Store those notification targets in struct ct_mixer instead. The mixer is
> per-card state and matches the lifetime of the controls created for that
> card.
> 
> Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com>

Applied now.  Thanks.


Takashi