Re: [PATCH] ACPI: Execute the _PTS method when system reboot

[Prarit Bhargava]

On 05/29/2016 11:28 PM, Ocean HY1 He wrote:
>> -----Original Message-----
>> From: Prarit Bhargava [mailto:prarit@xxxxxxxxxx]
>> Sent: Tuesday, May 24, 2016 6:16 PM
>> To: Ocean HY1 He; jcm@xxxxxxxxxx
>> Cc: linux-acpi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; David Tanaka;
>> Nagananda Chumbalkar; rjw@xxxxxxxxxxxxx; lenb@xxxxxxxxxx;
>> wefu@xxxxxxxxxx
>> Subject: Re: [PATCH] ACPI: Execute the _PTS method when system reboot
>>
>>
>>
>> On 05/24/2016 02:41 AM, Ocean HY1 He wrote:
>>> Hi Prarit and Jon,
>>>
>>> How do you think of this?
>>>
>>> Thanks.
>>>
>>> Ocean He / 何海洋
>>> 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: Ocean HY1 He
>>> Sent: Monday, May 16, 2016 11:04 AM
>>> To: rjw@xxxxxxxxxxxxx; lenb@xxxxxxxxxx
>>> Cc: linux-acpi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; David
>> Tanaka; Nagananda Chumbalkar
>>> Subject: RE: [PATCH] ACPI: Execute the _PTS method when system
>> reboot
>>>
>>> To whom may concern,
>>>
>>> A Lenovo feature depends on _PTS method execution when reboot. And
>> after check the ACPI spec, I think _PTS should be exectued when reboo.
>> This patch could fix the problem.
>>>
>>> Any comments of this patch? Many thanks!
>>>
>>> Ocean He / 何海洋
>>> 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: Ocean HY1 He
>>> Sent: Monday, May 09, 2016 1:50 PM
>>> To: rjw@xxxxxxxxxxxxx; lenb@xxxxxxxxxx
>>> Cc: linux-acpi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; David
>> Tanaka; Ocean HY1 He; Nagananda Chumbalkar
>>> Subject: [PATCH] ACPI: Execute the _PTS method when system reboot
>>>
>>> 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.
>>>
>>> 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");
>>
>> ^^^^
>> 	pr_debug("No _PTS object found.\n");
>>
>> It isn't a warning or error, so don't put the word "Failure" in there.
>>
>> Beyond that, looks entirely reasonable to me.
>>
>> P.
>>
> Hi Prarit,
> 
> The message outputs when _PTS is found but fail to execute. I copy this code
> from existed function acpi_sleep_tts_switch(). I just wants to keep new codes
> as the same style as existed codes. Make sense? ;-)

Not really.  "Failure" is something that QE groups look for when testing,
debugging, or verifying.  This message implies something went wrong when the
_PTS object is an optional implementation of ACPI.

P.

> 
> Ocean.
>>
>>> +	}
>>> +
>>> +	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);
>>> +
>>>  	return 0;
>>>  }
>>>