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From: "Ethin Probst" <harlydavidsen@gmail.com>
Date: Thu, 1 Jul 2021 13:10:45 -0500
Message-ID: <CAJQtwF3WnWCvgmfPJ6NFS9GuqwPdWeOZz1Nnn3WmeZm5A7xDmg@mail.gmail.com>
Subject: Re: [edk2-devel] EFI_AUDIO_OUTPUT_PROTOCOL: assistance with VirtIO initialization
To: Michael Brown <mcb30@ipxe.org>
Cc: devel@edk2.groups.io
Content-Type: text/plain; charset="UTF-8"

The first: I don't know how to retrieve the descriptors on the UEFI
API. I've looked at the Chaos Key DXE, if memory serves, or the
display port one -- one of the two. One of them contained a
ReadDescriptor() function, and so I've borrowed that, but that doesn't
really help much.

On 7/1/21, Michael Brown <mcb30@ipxe.org> wrote:
> On 01/07/2021 00:01, Ethin Probst wrote:
>> So Leif and I have been working on USB Audio but we've run into a snag.
>> We've encountered a problem -- neither of us knows enough about USB to
>> figure out how to get the class-specific AC interface descriptors, and
>> those contain vital information that I need to be able to control the
>> audio device.
>
> Do you mean that you can't figure out how to retrieve the descriptors
> via the UEFI APIs, or that you don't know how to interpret the
> descriptors after retrieval?
>
> Thanks,
>
> Michael
>


-- 
Signed,
Ethin D. Probst