Dear Takashi San,
I have now running Kernel 5.4.12 with your patch and attached here the 
requested information.

In kern.log you may want to check the lines starting from 1009 when 
attaching the device.

Thanks a lot
Tobias


Am 16.01.20 um 21:28 schrieb Takashi Iwai:
> On Thu, 16 Jan 2020 18:45:28 +0100,
> Tobias wrote:
>> I applied the patch and when connecting the Denon MC7000 the attached
>> is what dmesg shows...
>> Hope you can find something useful in there.
> Thanks.  This shows the validation error reported repeatedly at each
> access.  Hmm.
>
>> Please let me know, if I can be of any more help.
> Please give lsusb -v output for the device, too, as well as
> alsa-info.sh output (run with --no-upload option).
>
> And, be prepared for building the more recent kernel.  At least, the
> latest 5.4.y would be good -- otherwise there can be a chance you
> overlook something that was fixed already.
>
>
> Takashi