On Mon, Dec 20, 2021 at 11:01:56AM +0100, Oliver Neukum wrote:
>
> On 20.12.21 07:46, Ralf Beck wrote
> > One set with audio class specific interfaces for use by an audi
> > class driver. The other set with vendor specific interfaces for use
> > by the vendor driver. Obviously the class specific interfaces and
> > vendor specific interfaces are not intended to be use by a driver
> > simultaniously.
> Such devices are buggy. We usually define quirks for such devices.
> > There must be another solution to deal with this. It is unacceptable
> > to request a user of these devices to have to disablethe duplicate
> > endpoint check and recompile the kernel on every update in order to
> > be able to use their devices in vendor mode.
> I suggest you write a patch to introduce a quirk that disables one of the
> interfaces and disregards disabled interfaces for purposes of the check.
We already have USB_QUIRK_ENDPOINT_IGNORE (previously known as
USB_QUIRK_ENDPOINT_BLACKLIST) for this. See, for example:
184eead057cc ("USB: core: Fix regression in Hercules audio card")
and
bdd1b147b802 ("USB: quirks: blacklist duplicate ep on Sound Devices USBPre2")
Johan
