Am 25.06.19 um 09:54 schrieb Takashi Iwai:
> On Sat, 22 Jun 2019 22:55:25 +0200,
> Stefan Sauer wrote:
>>
>> So the first 8 controls are added somewhere else. Looks like this is from
>> mixer.c and after
>> echo -n 'file sound/usb/mixer.c +p' >/sys/kernel/debug/dynamic_debug/control
>> I get
>> [ 4405.855432] usb 1-2: [51] PU [KKKKKKKKKKKKKÃÃÃÃÃÃÃÃÃÃÃ Switch] ch = 1, val = 0/1
>> [ 4405.856423] usb 1-2: [52] PU [ Switch] ch = 1, val = 0/1
>
> This indicates that these weird names come from the two extension
> units id 51 and 52.
> Could you put some debug print in build_audio_procunit() like below?
I traced it down to this part from sound/usb/mixer.c:
nameid = uac_processing_unit_iProcessing(desc, state->mixer->protocol);
usb_audio_dbg(state->chip, "desc->bUnitID=%d, proto=%d, nameid=%d\n",
desc->bUnitID, state->mixer->protocol, nameid);
len = 0;
if (nameid) {
len = snd_usb_copy_string_desc(state->chip,
nameid,
kctl->id.name,
sizeof(kctl->id.name));
usb_audio_dbg(state->chip, "nameid=%d, len=%d, fallback name='%s'\n",
nameid, len, name);
}
[ 6241.045734] usb 1-2: desc->bUnitID=51, proto=32, nameid=90
[ 6241.045861] usb 1-2: nameid=90, len=35, fallback name='Extension Unit'
[ 6241.045868] usb 1-2: [51] PU [KKKKKKKKKKKKKÃÃÃÃÃÃÃÃÃÃÃ Switch] ch = 1, val = 0/1
[ 6241.046745] usb 1-2: desc->bUnitID=52, proto=32, nameid=82
[ 6241.046857] usb 1-2: nameid=82, len=1, fallback name='Extension Unit'
[ 6241.046862] usb 1-2: [52] PU [ Switch] ch = 1, val = 0/1
The device is using UAC_VERSION_2. The code in include/uapi/linux/usb/audio.h is
a bit hard to read since uac_mixer_unit_descriptor has a variable length and the
code is adding several offset, I'll need to add more printfs there to check if
it is correct. I am consulting
https://www.usb.org/sites/default/files/audio10.pdf but I am not sure if this
covers UAC2.
Stefan
>
>
> thanks,
>
> Takashi
>
> --- a/sound/usb/mixer.c
> +++ b/sound/usb/mixer.c
> @@ -2358,8 +2358,10 @@ static int build_audio_procunit(struct mixer_build *state, int unitid,
> for (info = list; info && info->type; info++)
> if (info->type == type)
> break;
> - if (!info || !info->type)
> + if (!info || !info->type) {
> + pr_info("XXX unit %d to default_info\n", unitid);
> info = &default_info;
> + }
>
> for (valinfo = info->values; valinfo->control; valinfo++) {
> __u8 *controls = uac_processing_unit_bmControls(desc, state->mixer->protocol);
> @@ -2375,8 +2377,11 @@ static int build_audio_procunit(struct mixer_build *state, int unitid,
> }
>
> map = find_map(state->map, unitid, valinfo->control);
> + if (map)
> + pr_info("XXX map found for unit %d\n", unitid);
> if (check_ignored_ctl(map))
> continue;
> +
> cval = kzalloc(sizeof(*cval), GFP_KERNEL);
> if (!cval)
> return -ENOMEM;
> @@ -2444,19 +2449,26 @@ static int build_audio_procunit(struct mixer_build *state, int unitid,
> kctl->private_free = snd_usb_mixer_elem_free;
>
> if (check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name))) {
> + pr_info("XXX name copied from map: '%s' for unit %d\n", kctl->id.name, unitid);
> /* nothing */ ;
> } else if (info->name) {
> strlcpy(kctl->id.name, info->name, sizeof(kctl->id.name));
> + pr_info("XXX name copied from info: '%s' for unit %d\n", kctl->id.name, unitid);
> } else {
> nameid = uac_processing_unit_iProcessing(desc, state->mixer->protocol);
> + pr_info("XXX nameid=%d, unit %d\n", nameid, unitid);
> len = 0;
> - if (nameid)
> + if (nameid) {
> len = snd_usb_copy_string_desc(state->chip,
> nameid,
> kctl->id.name,
> sizeof(kctl->id.name));
> - if (!len)
> + pr_info("XXX copy string desc '%s'\n", kctl->id.name);
> + }
> + if (!len) {
> strlcpy(kctl->id.name, name, sizeof(kctl->id.name));
> + pr_info("XXX copy default name '%s'\n", kctl->id.name);
> + }
> }
> append_ctl_name(kctl, " ");
> append_ctl_name(kctl, valinfo->suffix);
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