On Thu, Dec 17, 2020 at 3:12 PM Takashi Iwai <tiwai@xxxxxxx> wrote: > > Thanks. > > > Interface Association: > > bLength 8 > > bDescriptorType 11 > > bFirstInterface 2 > > bInterfaceCount 2 > > bFunctionClass 1 Audio > > bFunctionSubClass 2 Streaming > > bFunctionProtocol 0 > > iFunction 5 USB Microphone > > Interface Descriptor: > (snip) > > AudioStreaming Interface Descriptor: > > bLength 11 > > bDescriptorType 36 > > bDescriptorSubtype 2 (FORMAT_TYPE) > > bFormatType 1 (FORMAT_TYPE_I) > > bNrChannels 1 > > bSubframeSize 2 > > bBitResolution 16 > > bSamFreqType 1 Discrete > > tSamFreq[ 0] 8000 > > Endpoint Descriptor: > > bLength 9 > > bDescriptorType 5 > > bEndpointAddress 0x82 EP 2 IN > > bmAttributes 1 > > Transfer Type Isochronous > > Synch Type None > > Usage Type Data > > wMaxPacketSize 0x0100 1x 256 bytes > > bInterval 4 > > It's 4, and the same is set for all sample rates (8000, 16000, 44100, > 48000). > > If you don't tweak the datainterval, which error do you get? > The actual error message should appear before "... xx callbacks > suppressed" line. Without the tweak, only error messages are: kernel: usb 1-8: current rate 0 is different from the runtime rate 8000 kernel: usb 1-8: current rate 0 is different from the runtime rate 16000 kernel: usb 1-8: current rate 0 is different from the runtime rate 44100 kernel: usb 1-8: current rate 0 is different from the runtime rate 48000 kernel: usb 1-8: Warning! Unlikely big volume range (=4096), cval->res is probably wrong. kernel: usb 1-8: [3] FU [Mic Capture Volume] ch = 1, val = 0/4096/1 but recording from mic at any rate (8000, 16000, 44100, 48000) results in an incomprehensible sound, like Minion voice. With your patch 'ALSA: usb-audio: Disable sample read check if firmware doesn't give back' error messages have gone away, but result is the same: Minion voice. Thanks, Marco
