Rebooting fails with rcu_sched self-detected stall on CPU


(Christian Baumann) #1

Hello,

I have a problem with rebooting my sifive unleashed.

I flashed my SD-card according to the sifive/freedom-u-sdk v201908-branch with “MACHINE=freedom-u540 bitbake demo-coreip-cli”.

The system boots up fine. But if I try to restart the board, I get the following messages:

[   86.981976] systemd-shutdown[1]: Detaching DM devices.          
[   87.423510] reboot: Restarting system                           
[  108.422889] rcu: INFO: rcu_sched self-detected stall on CPU
[  108.427707] rcu:     0-....: (5249 ticks this GP) idle=eb6/1/0x4000000000000002 softirq=3623/3623 fqs=2592
[  108.437164]  (t=5250 jiffies g=2501 q=41)                       
[  108.441158] Task dump for CPU 0:                           
[  108.444369] systemd-shutdow R  running task        0     1      0 0x00000008                                
[  108.451400] Call Trace:                                 
[  108.453849] [<ffffffe00003d968>] walk_stackframe+0x0/0xa6
[  108.459220] [<ffffffe00003dace>] show_stack+0x2a/0x34
[  108.464262] [<ffffffe00005c64a>] sched_show_task+0xba/0x10c
[  108.469813] [<ffffffe000060bb0>] dump_cpu_task+0x3e/0x48
[  108.475112] [<ffffffe000089668>] rcu_dump_cpu_stacks+0x7c/0xb4
[  108.480925] [<ffffffe000088bb8>] rcu_sched_clock_irq+0x3de/0x532
[  108.486917] [<ffffffe00008d3d4>] update_process_times+0x22/0x4c
[  108.492821] [<ffffffe00009613e>] tick_periodic+0x42/0xd6
[  108.498115] [<ffffffe0000961f2>] tick_handle_periodic+0x20/0x5e
[  108.504028] [<ffffffe000452c54>] riscv_timer_interrupt+0x32/0x3a
[  108.510018] [<ffffffe0005772fc>] do_IRQ+0xa4/0xb8
[  108.514700] [<ffffffe00003c8a4>] ret_from_exception+0x0/0xc
[  108.520256] [<ffffffe00003d056>] machine_restart+0xc/0xe

The whole block (except the first two lines) are repeated every 63 seconds.

Any ideas what could be the problem or how to fix it?

Best regards
Christian


(Jim Wilson) #2

Restart isn’t supported yet. Use poweroff instead and then powercycle. If poweroff doesn’t work, then yes, that is a bug. I don’t actively follow linux kernel development, but I think that patches to make reset work have been proposed, and may land within a few versions.


(Paul Walmsley) #3

That’s a bug in Freedom-U SDK. Please report it on github: