Re: PNP0501 serial driver takes almost 2 seconds to suspend/resume (printk issue)

From: Andy Shevchenko
Date: Sun Jul 10 2022 - 15:40:05 EST

On Sat, Jul 9, 2022 at 10:48 PM John Ogness <john.ogness@xxxxxxxxxxxxx> wrote:
> On 2022-07-08, Todd Brandt <todd.e.brandt@xxxxxxxxxxxxxxx> wrote:
> > The dmesg logs are in the html timelines themselves, just click the
> > "dmesg" button in the upper right hand corner. The log button shows
> > all kinds of system info as well.
> Since the beginning of the kernel log is missing, I still do not see
> information about which serial driver you are using. But since it is
> x86, I'll assume it is an 8250.
> Looking at freeze-5.19.0-rc1-bad.html, at 3431.221039 we see that
> suspend_console() was called. The additional 1-second delay you are
> referring to would be 3432.436187, where serial is suspended. pr_flush()
> would have been satisfied when the message at 3431.221039 was
> printed. So the question is, why is there still printing going on?

It might be no_console_suspend hack. Are you, btw, aware of this ugly
hack in the kernel?

With Best Regards,
Andy Shevchenko