Re: [PREEMPT_RT] 8250 IRQ lockup when flooding serial console (was Re: [ANNOUNCE] v5.4.28-rt19)

[Sebastian Andrzej Siewior]

On 2020-04-23 14:34:37 [-0400], Steven Rostedt wrote:
> On Thu, 23 Apr 2020 09:06:01 -0400
> Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> 
> > BTW, I haven't released a new 5.4-rt because the default one is triggering
> > a large latency somewhere, and makes my tests fail. I'm trying to dig into
> > the cause when I get time.
> 
> Figured it out. Seems that starting with 5.4-rt, PREEMPT_RT now depends on
> CONFIG_EXPERT, which I didn't have set, and PREEMPT_RT was disabled when
> using my default config.
> 
> Had to add CONFIG_EXPERT to my default config to make it work again.

Yes, this changed upstream.

> Starting the tests over....
> 
> -- Steve

Sebastian