On Tue, Jan 26, 2021 at 08:56:29PM +0000, Edd Barrett wrote: > Hi, > > I've recently come across a uaudio device which doesn't work in OpenBSD: > > uaudio2 at uhub0 port 1 configuration 1 interface 3 "E+ Corp. DAC Audio" rev > 1.10/0.01 addr 2 > uaudio2: class v1, full-speed, async, channels: 2 play, 0 rec, 3 ctls > audio3 at uaudio2 > > When opening the audio device, the kernel reports `uaudio0: can't get iface > handle` in the dmesg buffer. > > I posted information about the device and sthen@ and kettenis@ spotted > the problem: the device exposes non-consecutive interface numbers, and > is thus not compliant with the USB standard. > > It has interfaces 0, 1 and 3, in that order. The audio stream is on > interface 3, which the kernel expects to find at index 3 in the ifaces > array, but actually it's at index 2! > > I've pasted a load of info about the device (lsusb and debug kernel > output) here: > https://gist.github.com/vext01/958756d0fd515cc321f99a3ee1e3351a > > The following diff makes this device work. It searches the ifaces array > in the event that the correct entry is not found at the expect index. > This should be a "no functional change" for all existing compliant > devices. > > I've tested this for the past two days and all seems well, but I'd like > some USB stack hackers to verify it. >
This also fixes another audio device. AFAICS this diff doesn't change the code-path for compliant devices, so I don't see how this could cause problems ok ratchov (could you split the long comment line, please)
