I'm in trouble to get some usb(4) devices working here. Devices are 
attached as ugen(4) and are driven by userspace (libusb) drivers/daemons.

As far as I can see what happens is that daemon opens ugen(4) device 
correctly and starts to poll(2) interrupt endpoint of the device (devices 
have single interface). The trouble is that poll(2) seems to ignore 
timeout. It doesn't return until there is data available in the 
descriptor. Ie I can make poll(2) to return with poking device, but till 
then it blocks.

Before I dig deep into areas I'm not familiar with ... Any ideas why and 
where it might happen? Anyone seen something like this?


-- 
Hasso Tepper