Regards, Ocean He SW Development Dept. Beijing Design Center Enterprise Product Group Mobile: 18911778926 E-mail: hehy1@xxxxxxxxxx No.6 Chuang Ye Road, Haidian District, Beijing, China 100085 > -----Original Message----- > From: Zheng, Lv [mailto:lv.zheng@xxxxxxxxx] > Sent: Friday, June 24, 2016 8:30 AM > To: Ocean HY1 He; Rafael J. Wysocki > Cc: lenb@xxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; David Tanaka; Nagananda Chumbalkar > Subject: RE: [PATCH] ACPI: Execute the _PTS method when system reboot > > Hi, > > > From: linux-acpi-owner@xxxxxxxxxxxxxxx [mailto:linux-acpi- > > owner@xxxxxxxxxxxxxxx] On Behalf Of Ocean HY1 He > > Subject: RE: [PATCH] ACPI: Execute the _PTS method when system > reboot > > > > Hi Rafael, > > Please see my reply in below. > > > > Regards, > > Ocean He > > SW Development Dept. > > Beijing Design Center > > Enterprise Product Group > > Mobile: 18911778926 > > E-mail: hehy1@xxxxxxxxxx > > No.6 Chuang Ye Road, Haidian District, Beijing, China 100085 > > > > > -----Original Message----- > > > From: Rafael J. Wysocki [mailto:rjw@xxxxxxxxxxxxx] > > > Sent: Wednesday, June 22, 2016 7:56 AM > > > To: Ocean HY1 He > > > Cc: lenb@xxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; > > > linux-kernel@xxxxxxxxxxxxxxx; David Tanaka; Nagananda Chumbalkar > > > Subject: Re: [PATCH] ACPI: Execute the _PTS method when system > > reboot > > > > > > On Monday, May 09, 2016 05:50:11 AM Ocean HY1 He wrote: > > > > The _PTS control method is defined in the section 7.4.1 of acpi 6.0 > > > > spec. The _PTS control method is executed by the OS during the > sleep > > > > transition process for S1, S2, S3, S4, and for orderly S5 shutdown. > > > > The sleeping state value (For example, 1, 2, 3, 4 or 5 for the S5 > > > > soft-off state) is passed to the _PTS control method. This method > > > > is called after OSPM has notified native device drivers of the sleep > > > > state transition and before the OSPM has had a chance to fully > > > > prepare the system for a sleep state transition. > > > > > > > > The _PTS control method provides the BIOS a mechanism for > > performing > > > > some housekeeping, such as writing the sleep type value to the > > > embedded > > > > controller, before entering the system sleeping state. > > > > > > > > According to section 7.5 of acpi 6.0 spec, _PTS should run after _TTS. > > > > > > > > Thus, a _PTS block notifier is added to the reboot notifier list so that > > > > the _PTS object will also be evaluated when the system reboot. > > > > > > So I understand why it may be necessary to evaluate _PTS before > > entering > > > S5, > > > but I'm totally unsure about reboot. > > > > > > What does reboot have to do with S5? > > > > > In ACPI spec, there is no explicit words saying _PTS should be > > executed when reboot. But reboot could be equal to the > > process S0->S5->S0. Thus _PTS should be executed when reboot. > > > > I am thinking this is the same as _TTS. In ACPI spec, there is also > > no explicit words saying _TTS should be executed when reboot. > > But kernel executes _TTS when reboot indeed. > [Lv Zheng] > What's the de-facto standard behavior here? > Lenovo should be able to modify BIOS, should you try to boot different > Windows clones to confirm the necessity of doing this? > > Thanks and best regards > -Lv > I have consulted Lenovo UEFI/BIOS archtect, David Tanaka. He says the de-facto standard behavior is that _PTS should be executed when reboot, at least for Windows. Windows does not differentiate OS reboot and shutdown. And, our test on Windows shows _PTS is executed when reboot actually. I try to find the difference between OS reboot and shutdown(S5) in ACPI spec, but I cann't find the answer. So, in my mind I consider reboot equals S0->S5->S0. Maybe you have evidence shows they are different, please let me know. It would help me a lot. Thanks. Ocean. > > > > > > Signed-off-by: Ocean He <hehy1@xxxxxxxxxx> > > > > Signed-off-by: Nagananda Chumbalkar <nchumbalkar@xxxxxxxxxx> > > > > --- > > > > drivers/acpi/sleep.c | 27 +++++++++++++++++++++++++++ > > > > 1 file changed, 27 insertions(+) > > > > > > > > diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c > > > > index 2a8b596..8b290fb 100644 > > > > --- a/drivers/acpi/sleep.c > > > > +++ b/drivers/acpi/sleep.c > > > > @@ -55,6 +55,26 @@ static struct notifier_block tts_notifier = { > > > > .priority = 0, > > > > }; > > > > > > > > +static int pts_notify_reboot(struct notifier_block *this, > > > > + unsigned long code, void *x) > > > > +{ > > > > + acpi_status status; > > > > + > > > > + status = acpi_execute_simple_method(NULL, "\\_PTS", > > > ACPI_STATE_S5); > > > > + if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) { > > > > + /* It won't break anything. */ > > > > + printk(KERN_NOTICE "Failure in evaluating _PTS object\n"); > > > > + } > > > > + > > > > + return NOTIFY_DONE; > > > > +} > > > > + > > > > +static struct notifier_block pts_notifier = { > > > > + .notifier_call = pts_notify_reboot, > > > > + .next = NULL, > > > > + .priority = 0, > > > > +}; > > > > + > > > > static int acpi_sleep_prepare(u32 acpi_state) > > > > { > > > > #ifdef CONFIG_ACPI_SLEEP > > > > @@ -896,5 +916,12 @@ int __init acpi_sleep_init(void) > > > > * object can also be evaluated when the system enters S5. > > > > */ > > > > register_reboot_notifier(&tts_notifier); > > > > + > > > > + /* > > > > + * According to section 7.5 of acpi 6.0 spec, _PTS should run after > > > > + * _TTS when the system enters S5. > > > > + */ > > > > + register_reboot_notifier(&pts_notifier); > > > > > > Why do you have to add a second notifier? > > > > > > Why can't _TTS and _PTS be evaluated from one notifier? > > > > > If execute _PTS method in tts_notify_reboot(), then it would break > > definition of tts_notify_reboot(). My intention is to keep new codes > > has limited impact on existed codes. > > Of course, it's possible to merge _TTS and _PTS into one unified notifier. > > The advantage is more actions could be added into the unified notifier > in > > future. > > Which way you prefer? > > > > + > > > > return 0; > > > > } > > > > > > > > > > Thanks, > > > Rafael > > > > ��칻 �&�~�&���+- > > > ��ݶ��w��˛���m�b��Zr����^n�r���z���h����&�� �G���h�(� > 階 > > �ݢj"���m�����z�ޖ���f���h���~�m� ��.n��������+%������w��{.n�����{�����ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
