Re: [RFC][PATCH] ACPI: tracing: Have ACPI debug go to tracing ring buffer

From: Rafael J. Wysocki
Date: Fri Dec 30 2022 - 10:52:59 EST


On Thu, Dec 15, 2022 at 9:13 PM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> On Thu, 15 Dec 2022 14:52:48 -0500
> Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> wrote:
>
> > Another approach could be to always enable the trace event by default,
> > if the CONFIG is turned on. Or do a printk() telling the user about
> > the event to enable, so they know why their trace buffer is empty.
>
> Yeah, that is another option.
>
> And, yes I need to document it better. I started to, but then decided to
> hold off until I get some feedback in case this is rejected.
>
> >
> > Up to you and the ACPI maintainers. ;-)
>
> I'm going to guess I may not hear back until the new year. I'm fine with
> that :-)

It's just a couple of days, but still.

Personally, I would use a command line option to control the behavior
and the Kconfig option to provide its default value.

This way it can be flipped without rebuilding the kernel if need be.

I would also make the ACPI debug output go into the trace buffer so
long as the Kconfig option is not changed or the command line option
is not flipped.

Cheers!