Am 26.06.19 um 22:06 schrieb Stefan Sauer:
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
and with the bUnitID I get to these descriptors from lsusb:
AudioControl Interface Descriptor: bLength 16 bDescriptorType 36 bDescriptorSubtype 9 (EXTENSION_UNIT) bUnitID 51 wExtensionCode 0x0000 bNrInPins 1 baSourceID(0) 2 bNrChannels 20 bmChannelConfig 0x00000000 iChannelNames 0 bmControls 0x03 Enable Control (read/write) iExtension 0 AudioControl Interface Descriptor: bLength 16 bDescriptorType 36 bDescriptorSubtype 9 (EXTENSION_UNIT) bUnitID 52 wExtensionCode 0x0000 bNrInPins 1 baSourceID(0) 1 bNrChannels 20 bmChannelConfig 0x00000000 iChannelNames 0 bmControls 0x03 Enable Control (read/write) iExtension 0
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);- 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 */ ;pr_info("XXX name copied from info: '%s' for unit %d\n", kctl->id.name, unitid);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);}
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