On 03/07/2016 07:34 PM, Ludovic Rousseau wrote: > printf("fds: %d %d\n", fds[0].revents, fds[1].revents);
fds: 0 1 always I also printed udev_dev from udev_monitor_receive_device() it's always null So we get fds[1].revents but don't get anything from udev_monitor_receive_device() so it's looping forever. You may try to trigger the bug from your side: It probably requires the same versions as me. kernel 4.3.0-1-amd64 libusb-1.0-0 2:1.0.20-1 libudev1 229-2 I've a Yubikey neo-n plugged in. I start pcscd. I plug a usb hub (or anything else) => CPU at 100%