[U-Boot] Reboot is broken on RockPro64 with mainline u-boot and ATF

[Vasily Khoruzhick]

Hey guys,

Looks like reboot is broken on RockPro64 (RK3399-based) with mainline
u-boot and ATF (ATF already has a fix [1]).

When I type 'reboot' in linux I get back to u-boot, but subsequent
linux boot hangs in most cases. Sometimes I get this warning:

[   62.400363] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
[   62.418095] rcu:     4-...!: (3 ticks this GP)
idle=332/1/0x4000000000000000 softirq=23/24 fqs=13
[   62.444137] Task dump for CPU 4:
[   62.453791] kworker/4:1     R  running task        0    42      2 0x0000002a
[   62.474907] Workqueue: pm genpd_power_off_work_fn
[   62.489013] rcu: rcu_sched kthread starved for 5976 jiffies! g-1147
f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
[   62.519205] rcu: RCU grace-period kthread stack dump:
[   62.534316] rcu_sched       R  running task        0    10      2 0x00000028

I already checked that regulators are configured correctly, also I
tried to disable big CPU cluster in linux and re-initializing CPU
voltages in u-boot but unfortunately nothing helps.

There were other reports on #linux-rockchip at freenode that reboot is broken.

Any ideas how to debug it or what could be wrong?

Regards,
Vasily

[1] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2512