linux-kernel - Re: [PATCH] RFC syscore: add suspend type to syscore

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Message-ID: <CAG7+-3N=vonV+8y0bTXXh72vJGUqMrjyu_d4sztzpPkrPj7KeQ@mail.gmail.com>
Date:   Fri, 5 Feb 2021 18:27:53 +0800
From:   Ruifeng Zhang <ruifeng.zhang0110@...il.com>
To:     "Rafael J. Wysocki" <rafael@...nel.org>
Cc:     Greg KH <gregkh@...uxfoundation.org>, ruifeng.zhang1@...soc.com,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Chunyan Zhang <chunyan.zhang@...soc.com>, ke.wang@...soc.com,
        nianfu.bai@...soc.com, orson.zhai@...soc.com
Subject: Re: [PATCH] RFC syscore: add suspend type to syscore

Rafael J. Wysocki <rafael@...nel.org> 于2021年2月4日周四 下午9:38写道：
>
> On Thu, Feb 4, 2021 at 10:07 AM Ruifeng Zhang
> <ruifeng.zhang0110@...il.com> wrote:
> >
> > Greg KH <gregkh@...uxfoundation.org> 于2021年1月29日周五 下午4:53写道：
> > >
> > > On Fri, Jan 29, 2021 at 04:27:26PM +0800, Ruifeng Zhang wrote:
> > > > From: Ruifeng Zhang <ruifeng.zhang1@...soc.com>
> > > >
> > > > Suspend type contains s2ram and s2idle, but syscore is only
> > > > available for S2RAM.
> > >
> > > Who else needs this?
> > In the s2idle suspend and resume, some vendors want to do some
> > things, for example the vendor implemented the watchdog driver.
>
> Do that in the platform operations then.
>
> Adding the syscore stuff to the suspend-to-idle flow is not an option, sorry.
Excause me, I really still want to know the reason.
My requirement is that the watchdog need disable when the system s2idle.
If don't, the watchdog will bark when system resume.
>
> > The GKI requires that no modification of the kernel source is allowed,
> > so an syscore_s2idle is added for use.
>
> The GKI rules are not a mainline kernel concern.
>
> > The reason device_suspend was not chosen was that I wanted it to
> > monitor for longer periods, such as between device_suspend and
> > syscore_suspend.
> > >
> > > > S2idle requires a similar feature, so a new parameter
> > > > "enum suspend_type" is added to distinguish it.
> > >
> > > Who requires this export?
> > >
> > > I don't see a user of this new code/api in this patch, so why would it
> > > be accepted?
> > >
> > > Also, you are doing many different things in the same patch, please
> > > break this up into a patch series where you only do one logical change
> > > at a time.
> > I think it's only one things in patch
> > 0001-RFC-syscore-add-suspend-type-to-syscore.patch,
> > add a new s2ildle type for syscore.
> > >
> > > thanks,
> > >
> > > greg k-h
> >
> > From 1abd09045639dafdbf713514d4f1323b572dd2ec Mon Sep 17 00:00:00 2001
> > From: Ruifeng Zhang <ruifeng.zhang1@...soc.com>
> > Date: Thu, 4 Feb 2021 13:29:56 +0800
> > Subject: [PATCH 2/2] RFC time: add syscore suspend ops to s2idle
> >
> > Some vendors need do more things when s2idle.
> >
> > The required GKI does not allow modification of the
> > kernel source code, so provide the syscore operation
> > interface.
>
> No, this absolutely is a bad idea.
>
> > Signed-off-by: Ruifeng Zhang <ruifeng.zhang1@...soc.com>
> > ---
> >  kernel/time/tick-common.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
> > index 9d3a22510bab..8c4509250456 100644
> > --- a/kernel/time/tick-common.c
> > +++ b/kernel/time/tick-common.c
> > @@ -11,6 +11,7 @@
> >  #include <linux/err.h>
> >  #include <linux/hrtimer.h>
> >  #include <linux/interrupt.h>
> > +#include <linux/list.h>
> >  #include <linux/nmi.h>
> >  #include <linux/percpu.h>
> >  #include <linux/profile.h>
> > @@ -528,6 +529,7 @@ void tick_freeze(void)
> >         trace_suspend_resume(TPS("timekeeping_freeze"),
> >                      smp_processor_id(), true);
> >         system_state = SYSTEM_SUSPEND;
> > +       syscore_suspend(SUSPEND_S2IDLE);
> >         sched_clock_suspend();
> >         timekeeping_suspend();
> >     } else {
> > @@ -553,6 +555,7 @@ void tick_unfreeze(void)
> >     if (tick_freeze_depth == num_online_cpus()) {
> >         timekeeping_resume();
> >         sched_clock_resume();
> > +       syscore_resume(SUSPEND_S2IDLE);
> >         system_state = SYSTEM_RUNNING;
> >         trace_suspend_resume(TPS("timekeeping_freeze"),
> >                      smp_processor_id(), false);
> > --
> > 2.17.1
> >
> > Greg KH <gregkh@...uxfoundation.org> 于2021年1月29日周五 下午4:53写道：
> > >
> > > On Fri, Jan 29, 2021 at 04:27:26PM +0800, Ruifeng Zhang wrote:
> > > > From: Ruifeng Zhang <ruifeng.zhang1@...soc.com>
> > > >
> > > > Suspend type contains s2ram and s2idle, but syscore is only
> > > > available for S2RAM.
> > >
> > > Who else needs this?
> > >
> > > > S2idle requires a similar feature, so a new parameter
> > > > "enum suspend_type" is added to distinguish it.
> > >
> > > Who requires this export?
> > >
> > > I don't see a user of this new code/api in this patch, so why would it
> > > be accepted?
> > >
> > > Also, you are doing many different things in the same patch, please
> > > break this up into a patch series where you only do one logical change
> > > at a time.
> > >
> > > thanks,
> > >
> > > greg k-h