FYI, we noticed the following commit: https://github.com/0day-ci/linux Ruslan-Bilovol/USB-Audio-Gadget-refactoring/20160524-075634 commit ab3455d638a872d4e4dc6562347d494fca8fd756 ("usb: gadget: f_uac2: remove platform driver/device creation") on test machine: vm-kbuild-yocto-x86_64: 1 threads qemu-system-x86_64 -enable-kvm -cpu SandyBridge with 320M memory caused below changes: [ 39.403262] g_audio gadget: unable to register OSS PCM device 0:0 FYI, raw QEMU command line is: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -kernel /pkg/linux/x86_64-randconfig-s2-05270032/gcc-6/ab3455d638a872d4e4dc6562347d494fca8fd756/vmlinuz-4.6.0-rc3-00058-gab3455d -append 'root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-kbuild-yocto-x86_64-36/bisect_boot-1-yocto-minimal-x86_64.cgz-x86_64-randconfig-s2-05270032-ab3455d638a872d4e4dc6562347d494fca8fd756-20160527-68586-3w5kf5-0.yaml ARCH=x86_64 kconfig=x86_64-randconfig-s2-05270032 branch=linux-devel/devel-hourly-2016052621 commit=ab3455d638a872d4e4dc6562347d494fca8fd756 BOOT_IMAGE=/pkg/linux/x86_64-randconfig-s2-05270032/gcc-6/ab3455d638a872d4e4dc6562347d494fca8fd756/vmlinuz-4.6.0-rc3-00058-gab3455d max_uptime=600 RESULT_ROOT=/result/boot/1/vm-kbuild-yocto-x86_64/yocto-minimal-x86_64.cgz/x86_64-randconfig-s2-05270032/gcc-6/ab3455d638a872d4e4dc6562347d494fca8fd756/0 LKP_SERVER=inn earlyprintk=ttyS0,115200 systemd.log_level=err debug apic=debug sysrq_always_enabled rcupdate.rcu_cpu_stall_timeout=100 panic=-1 softlockup_panic=1 nmi_watchdog=panic oops=panic load_ramdisk=2 prompt_ramdisk=0 console=ttyS0,115200 console=tty0 vga=normal rw ip=::::vm-kbuild-yocto-x86_64-36::dhcp drbd.minor_count=8' -initrd /fs/sde1/initrd-vm-kbuild-yocto-x86_64-36 -m 320 -smp 1 -device e1000,netdev=net0 -netdev user,id=net0 -boot order=nc -no-reboot -watchdog i6300esb -rtc base=localtime -drive file=/fs/sde1/disk0-vm-kbuild-yocto-x86_64-36,media=disk,if=virtio -pidfile /dev/shm/kboot/pid-vm-kbuild-yocto-x86_64-36 -serial file:/dev/shm/kboot/serial-vm-kbuild-yocto-x86_64-36 -daemonize -display none -monitor null Thanks, Xiaolong