On 22.04.2013 21:23, Torstein Hegge wrote:
> On Mon, Apr 22, 2013 at 20:44:40 +0200, Daniel Mack wrote:
>> Also, the lsusb dumps don't contain a audio specific header descriptor,
>> which normally looks like this:
>>
>> AudioControl Endpoint Descriptor:
>> bLength 7
>> bDescriptorType 37
>> bDescriptorSubtype 1 (EP_GENERAL)
>> bmAttributes 0x01
>> Sampling Frequency
>> bLockDelayUnits 0 Undefined
>> wLockDelay 0 Undefined
>>
>> And without the "Sampling Frequency" bit in bmAttributes, the driver
>> will bail out early (clock.c):
>
> I think it has the class specific endpoint descriptor, but it is in
> front of the standard endpoint descriptor. From the 'lsusb -v':
>
> AudioStreaming Interface Descriptor:
> bLength 14
> bDescriptorType 36
> bDescriptorSubtype 2 (FORMAT_TYPE)
> bFormatType 1 (FORMAT_TYPE_I)
> bNrChannels 2
> bSubframeSize 2
> bBitResolution 16
> bSamFreqType 2 Discrete
> tSamFreq[ 0] 16000
> tSamFreq[ 1] 48000
> ** UNRECOGNIZED: 07 25 01 81 02 00 00
> Endpoint Descriptor:
> bLength 9
> bDescriptorType 5
> bEndpointAddress 0x03 EP 3 OUT
> bmAttributes 1
> Transfer Type Isochronous
> Synch Type None
> Usage Type Data
> wMaxPacketSize 0x00c0 1x 192 bytes
> bInterval 1
> bRefresh 0
> bSynchAddress 0
>
> The UNRECOGNIZED bit matches the missing AudioControl endpoint
> descriptor.
>
> Even if this is against the specification, devices that does this is out
> there. I have seen the same thing on a Sennheiser BTD-500, but that only
> supports one frequency, so I didn't hit this problem.
But it should still complain about "no or invalid class specific
endpoint descriptor", right?
If you have time, please check the attached (totally untested) patch.
Let's see.
Yves - did you ever compile and run your own kernel? Then please also
try this patch.
Thanks,
Daniel
diff --git a/sound/usb/stream.c b/sound/usb/stream.c
index 8951f77..67617e8 100644
--- a/sound/usb/stream.c
+++ b/sound/usb/stream.c
@@ -393,6 +393,11 @@ static int parse_uac_endpoint_attributes(struct snd_usb_audio *chip,
if (!csep && altsd->bNumEndpoints >= 2)
csep = snd_usb_find_desc(alts->endpoint[1].extra, alts->endpoint[1].extralen, NULL, USB_DT_CS_ENDPOINT);
+ /* if we still haven't found an uac endpoint descriptor, search the
+ * entire interface */
+ if (!csep)
+ csep = snd_usb_find_desc(alts->extra, alts->extralen, NULL, USB_DT_CS_ENDPOINT);
+
if (!csep || csep->bLength < 7 ||
csep->bDescriptorSubtype != UAC_EP_GENERAL) {
snd_printk(KERN_WARNING "%d:%u:%d : no or invalid"
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