[PATCH] ALSA: aoa: onyx: Update IEC958 sample-rate status for PCM playback

From: Cássio Gabriel

Date: Thu Apr 02 2026 - 23:47:32 EST


onyx_prepare() accepts 32/44.1/48 kHz PCM playback, but it leaves the
Onyx IEC958 sample-rate status bits at the driver's initial 44.1 kHz
setting in DIG_INFO3. As a result, 32 kHz and 48 kHz PCM streams
advertise a stale IEC958 sample rate unless userspace rewrites IEC958
Playback Default first.

Update only the consumer sample-frequency bits in DIG_INFO3 from the PCM
runtime during prepare, resolving the long-standing FIXME in the PCM
playback path while leaving the other user-controlled IEC958 status bits
unchanged.

Mark IEC958 Playback Default as volatile as well, since prepare() now
changes the exposed register contents outside the control put callback.

Signed-off-by: Cássio Gabriel <cassiogabrielcontato@xxxxxxxxx>
---
sound/aoa/codecs/onyx.c | 37 +++++++++++++++++++++++++++++++++----
1 file changed, 33 insertions(+), 4 deletions(-)

diff --git a/sound/aoa/codecs/onyx.c b/sound/aoa/codecs/onyx.c
index 04961c456d2c..6e2da2aca2ab 100644
--- a/sound/aoa/codecs/onyx.c
+++ b/sound/aoa/codecs/onyx.c
@@ -32,6 +32,7 @@
#include <linux/module.h>
#include <linux/of.h>
#include <linux/slab.h>
+#include <sound/asoundef.h>
MODULE_AUTHOR("Johannes Berg <johannes@xxxxxxxxxxxxxxxx>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("pcm3052 (onyx) codec driver for snd-aoa");
@@ -514,8 +515,36 @@ static int onyx_spdif_put(struct snd_kcontrol *kcontrol,
return 1;
}

+static int onyx_set_spdif_pcm_rate(struct onyx *onyx, unsigned int rate)
+{
+ u8 dig_info3, fs;
+
+ switch (rate) {
+ case 32000:
+ fs = IEC958_AES3_CON_FS_32000;
+ break;
+ case 44100:
+ fs = IEC958_AES3_CON_FS_44100;
+ break;
+ case 48000:
+ fs = IEC958_AES3_CON_FS_48000;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (onyx_read_register(onyx, ONYX_REG_DIG_INFO3, &dig_info3))
+ return -EBUSY;
+ dig_info3 = (dig_info3 & ~IEC958_AES3_CON_FS) | fs;
+ if (onyx_write_register(onyx, ONYX_REG_DIG_INFO3, dig_info3))
+ return -EBUSY;
+
+ return 0;
+}
+
static const struct snd_kcontrol_new onyx_spdif_ctrl = {
- .access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
+ .access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
+ SNDRV_CTL_ELEM_ACCESS_VOLATILE,
.iface = SNDRV_CTL_ELEM_IFACE_PCM,
.name = SNDRV_CTL_NAME_IEC958("",PLAYBACK,DEFAULT),
.info = onyx_spdif_info,
@@ -695,9 +724,9 @@ static int onyx_prepare(struct codec_info_item *cii,
case 32000:
case 44100:
case 48000:
- /* these rates are ok for all outputs */
- /* FIXME: program spdif channel control bits here so that
- * userspace doesn't have to if it only plays pcm! */
+ if (onyx->codec.connected & 2)
+ return onyx_set_spdif_pcm_rate(onyx,
+ substream->runtime->rate);
return 0;
default:
/* got some rate that the digital output can't do,

---
base-commit: f16695c0dc9db64f0a5a9871a10b70daee2653e3
change-id: 20260401-onyx-spdif-pcm-rate-ec45243ae8a3

Best regards,
--
Cássio Gabriel <cassiogabrielcontato@xxxxxxxxx>