Hi ALSA ML I'm now using buildroot, and want to use aplay/arecord in the same time with -d option. This works for me aplay -d 3 xxx And this works for me, too arecord -d 3 yyy But, this doesn't work, and system will hung up aplay -d 3 xxx & arecord -d 3 yyy Sometimes it will indicates this message rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-....: (1 GPs behind) idle=496/0/0x1 softirq=228/228 fqs=2172 (detected by 1, t=6502 jiffies, g=-103, q=17) Task dump for CPU 0: task:swapper/0 state:R running task stack: 0 pid: 0 ppid: 0 flags:0x0000002a Call trace: __switch_to+0x144/0x1a0 init_task+0x0/0x1780 ... Do you know why this happen ? Thank you for your help !! Best regards --- Kuninori Morimoto