Re: [serial] 679193b7ba: BUG:spinlock_bad_magic_on_CPU

[Andy Shevchenko]

On Sun, Aug 2, 2020 at 8:54 AM kernel test robot <lkp@xxxxxxxxx> wrote:
>
> Greeting,
>
> FYI, we noticed the following commit (built with gcc-9):
>
> commit: 679193b7baf8d88e41cbeb397ca17f797654947d ("serial: 8250: Let serial core initialise spin lock")
> https://git.kernel.org/cgit/linux/kernel/git/gregkh/tty.git tty-next
>
>
> in testcase: boot
>
> on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
>
> caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
>
>
> +-------------------------------+------------+------------+
> |                               | f3af1b68fc | 679193b7ba |
> +-------------------------------+------------+------------+
> | boot_successes                | 4          | 0          |
> | boot_failures                 | 0          | 4          |
> | BUG:spinlock_bad_magic_on_CPU | 0          | 4          |
> +-------------------------------+------------+------------+
>
>
> If you fix the issue, kindly add following tag
> Reported-by: kernel test robot <lkp@xxxxxxxxx>

Thanks for the report. I didn't see it on real hardware though. Maybe
because of timing (race?) differences.

Greg, I think the best is to revert the change until I will have better one.

-- 
With Best Regards,
Andy Shevchenko