Re: Help me fix a regression caused by 56b9918490 (PM: sleep: Simplify suspend-to-idle control flow)

From: "Rafael J. Wysocki" <rafael@kernel.org>
To: "Kenneth R. Crudup" <kenny@panix.com>
Cc: Rafael Wysocki <rafael.j.wysocki@intel.com>,
	Linux PM <linux-pm@vger.kernel.org>
Subject: Re: Help me fix a regression caused by 56b9918490 (PM: sleep: Simplify suspend-to-idle control flow)
Date: Fri, 22 Nov 2019 13:45:09 +0100	[thread overview]
Message-ID: <CAJZ5v0gKvDb8=Y04DB3wQe0rK8Zfw5yNuAybV980ozxfmem=BQ@mail.gmail.com> (raw)
In-Reply-To: <CAJZ5v0jQ3RY8An+V2VYH+ZKLC6=HrCYUMomM6jyEXJ47aeLT+A@mail.gmail.com>

On Fri, Nov 22, 2019 at 11:12 AM Rafael J. Wysocki <rafael@kernel.org> wrote:
>
> On Fri, Nov 22, 2019 at 1:28 AM Kenneth R. Crudup <kenny@panix.com> wrote:
> >
> >
> > I've been running Linus' tip for a while, mostly to get the PM improvements
> > on s2idle (I hate this mode so much- I'm tired of taking a warm laptop out
> > of my bag) and I'd reported after a previous merge to Linus' tip from pm-next:
> >
> > On Wed, 18 Sep 2019, Kenneth R. Crudup wrote:
> >
> > > - Randomly, if left suspended, nothing other than a hard power off will get
> > >   it back  ...  It appears "ec_no_wakeup=1" doesn't have this issue

BTW, is the ec_no_wakeup=1 workaround still effective?

If so, does the lid and/or power button wake up the system from
suspend with ec_no_wakeup=1?

> > So I noticed this bug seems to only happen if the laptop is plugged in and
> > charging- but only if the battery is < 100%; now that I had a real failure
> > mode I started bisecting, and I traced it to 56b991849, "PM: sleep: Simplify
> > suspend-to-idle control flow".
> >
> > What happens is I'll initiate a suspend, then when I try to resume the power
> > LED doesn't come on, and the machine is completely unresponsive. I have to
> > force a reset by holding the power key.
> >
> > I'd like to help you fix this issue; I figure if it's affecting my device
> > it's affecting others, too. I'm quite proficient with the kernel overall,
> > but know very little about ACPI or the EC. I'm assuming- totally wild guess-
> > that when we get some of those EC GPEs(?) while suspended(?) we're panic()ing
> > or hanging somewhere so the BIOS is getting hung up and the whole system is
> > stalled out.
> >
> > Where should I begin to help debug this? I have EFI store set up so BUG_ON()s
> > et al.  will dump there for retrival later if inserting those at critical
> > places could help.
>
> First off, please try to change the sleep_no_lps0 ACPI module
> parameter (/sys/module/acpi/parameters/sleep_no_lps0) to 1 and see if
> that makes any difference.  If it helps, I don't think we can do much
> except for blacklisting your machine.