Re: [PATCH] USB: Add quirk for WORLDE easykey.25 MIDI keyboard

From: LukÃÅ LalinskÃ
Date: Tue Jan 24 2017 - 02:38:24 EST


On Tue, Jan 24, 2017 at 8:32 AM, Oliver Neukum <oneukum@xxxxxxxx> wrote:
> Am Montag, den 23.01.2017, 19:36 +0100 schrieb LukÃÅ LalinskÃ:
>> I have uploaded both captures here -
>> https://gist.github.com/lalinsky/83148a827d5cd43e79e377d8e1b5ed0d
>
> Indeed it is does not set a configuration. Either the capture
> is incomplete or device and host violate the standard. A device
> may be left unconfigured.

Is this may or may not? I'm not familiar with USB, so I assumed if
there is only one configuration and there is always one active, it
does not need to be set explicitly because the correct one is already
active.

> We need to read the descriptors even if we
> see only one configuration to get the power budgeting right.

Aren't those in the CONFIGURATION descriptors? Reading the STRING
descriptor is probably only useful if you need to print the
configuration details somewhere.

> Does the device work without any .ini file?

Yes. It's a standard MIDI device, no configuration is required.

Lukas