Re: [PATCH 0/2] PM / core: genpd fix and pm_runtime_force_suspend|resume() rework

From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Linux PM <linux-pm@vger.kernel.org>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Linux-Renesas <linux-renesas-soc@vger.kernel.org>
Subject: Re: [PATCH 0/2] PM / core: genpd fix and pm_runtime_force_suspend|resume() rework
Date: Sat, 13 Jan 2018 01:38:19 +0100	[thread overview]
Message-ID: <12351114.Ym7QOfxZhK@aspire.rjw.lan> (raw)
In-Reply-To: <CAMuHMdX6dJzOcxkWyDR6anpcwZU5fy03sTeChEp35KY0d40iFg@mail.gmail.com>

On Friday, January 12, 2018 3:31:09 PM CET Geert Uytterhoeven wrote:
> Hi Rafael,
> 
> On Fri, Jan 12, 2018 at 2:00 PM, Rafael J. Wysocki <rjw@rjwysocki.net> wrote:
> > This comes from the recent discussion/testing effort that ensued after my
> > pm_runtime_force_suspend|resume() changes proposal:
> >
> > https://marc.info/?t=151497772000004&r=1&w=2
> >
> > Patch [1/2] basically is https://patchwork.kernel.org/patch/10152873/ rebased
> > on top of the current linux-next branch of the linux-pm.git tree (the relevant
> > part should be there in the linux-next tree proper ATM).  It applies on top
> > of https://patchwork.kernel.org/patch/10156077/ which should apply to the Linus'
> > tree cleanly.
> >
> > Patch [2/2] is a resend of https://patchwork.kernel.org/patch/10142047/ with
> > a very minor changelog modification and the R-b tag from Ulf.
> >
> > Geert, if possible, please test this on the Renesas systems that had the
> > problem with https://patchwork.kernel.org/patch/10142047/ previously and let
> > me know if you still see issues.
> 
> I've tested this on two very similar systems: Salvator-XS with R-Car H3 ES2.0,
> and Salvator-X with R-Car M3-W ES1.0.
> 
> On the M3-based system, everything seems to work fine.

Good.

> On the H3-based system, the serial console (the /dev/ttySC0 device, not kernel
> serial output) is dead after resume from s2ram, with and without
> no_console_suspend.
> 
> With no_console_suspend, I see:
> 
>     ttySC ttySC0: 1 input overrun(s)
> 
> after typing on the serial console, so it looks like an interrupt problem.
> 
> This issue seems to be caused by patch [1/2]. But I have no idea what's
> really happening, and why the two systems behave differently.

Well, that's not dramatic.

Let's make a deal that we'll fix this on top of [1/2].

Which driver is this BTW?  sh-sci?  That one doesn't even support runtime
PM, confusingly enough.

> Oh well, have a nice weekend!

Thanks, you too!