Date:	Sat, 11 Jul 2015 12:42:56 +0530
From:	Anand Moon <linux.amoon@...il.com>
To:	Krzysztof Kozlowski <k.kozlowski@...sung.com>
Cc:	Sangbeom Kim <sbkim73@...sung.com>,
	Liam Girdwood <lgirdwood@...il.com>,
	Mark Brown <broonie@...nel.org>,
	Linux Kernel <linux-kernel@...r.kernel.org>,
	"linux-samsung-soc@...r.kernel.org" 
	<linux-samsung-soc@...r.kernel.org>
Subject: Re: [PATCH] regulator: s2mps11: Added shutdown function to poweroff Odroid-XU3

Hi Krzysztof,

On 24 June 2015 at 16:27, Krzysztof Kozlowski <k.kozlowski@...sung.com> wrote:
> 2015-06-24 19:32 GMT+09:00 Anand Moon <linux.amoon@...il.com>:
>> Hi Krzysztof,
>>
>> On 24 June 2015 at 13:27, Krzysztof Kozlowski <k.kozlowski@...sung.com> wrote:
>>> 2015-06-24 16:16 GMT+09:00 Anand Moon <linux.amoon@...il.com>:
>>>> Added .shutdown function to s2mps11 to help poweroff the board succefully.
>>>
>>> s/succefully/successfully/
>>>
>>>> The device drivers set the register to turn off the PMIC.
>>>
>>> Driver or drivers?
>>>
>>>>
>>>> Signed-off-by: Anand Moon <linux.amoon@...il.com>
>>>> ---
>>>> Changes fixes the poweroff
>>>> root@...oidxu3:~# poweroff
>>>>
>>>> Broadcast message from root@...oidxu3
>>>>         (/dev/ttySAC2) at 13:08 ...
>>>>
>>>> The system is going down for power off NOW!
>>>> root@...oidxu3:~# wait-for-state stop/waiting
>>>>  * Stopping rsync daemon rsync                                           [ OK ]
>>>>  * Stopping RDP Session manager                                          [ OK ]
>>>>  * Stopping NTP server ntpd                                              [ OK ]
>>>>  * Asking all remaining processes to terminate...                        [ OK ]
>>>>  * All processes ended within 1 seconds...                               [ OK ]
>>>> nm-dispatcher.action: Caught signal 15, shutting down...
>>>> ModemManager[2134]: <warn>  Could not acquire the 'org.freedesktop.ModemManager1' service name
>>>>
>>>> ModemManager[2134]: <info>  ModemManager is shut down
>>>>
>>>>  * Unmounting temporary filesystems...                                   [ OK ]
>>>>  * Deactivating swap...                                                  [ OK ]
>>>>  * Unmounting local filesystems...                                       [ OK ]
>>>>  * Will now halt
>>>> [  209.020280] reboot: Power down
>>>> [  209.122039] Power down failed, please power off system manually.
>>>> ---
>>>>  drivers/regulator/s2mps11.c | 8 ++++++++
>>>>  1 file changed, 8 insertions(+)
>>>>
>>>> diff --git a/drivers/regulator/s2mps11.c b/drivers/regulator/s2mps11.c
>>>> index ff82811..871f7b8 100644
>>>> --- a/drivers/regulator/s2mps11.c
>>>> +++ b/drivers/regulator/s2mps11.c
>>>> @@ -1060,6 +1060,13 @@ out:
>>>>         return ret;
>>>>  }
>>>>
>>>> +static void s2mps11_pmic_shutdown(struct platform_device *pdev)
>>>> +{
>>>> +       struct sec_pmic_dev *iodev = dev_get_drvdata(pdev->dev.parent);
>>>> +
>>>> +       regmap_update_bits(iodev->regmap_pmic, S2MPS11_REG_CTRL1, 0xff, 0x00);
>>>
>>> This looks odd to me and interesting in the same time...
>>> 1. Why clearing all of the fields from the register? Don't you want to
>>> clear only one of it?
>>
>> I have followed what the hardkernel source code point at this point.
>> I will look into which bit need to clear/set to power off successful.
>
> Following other tree is not enough, even when it solves some one
> problem. Drivers could be used on different boards, where hardkernel
> patches were not tested. This driver is used on many boards so please
> explain exactly what is the cause of problem, what have to be done and
> how patch achieves this. Such explanation helps understanding impact
> on other boards.
>
>>
>>> 2. What exactly you want to do here? What is expected behaviour?
>>
>> When you power off the board dose not power off cleanly.
>> [  209.122039] Power down failed, please power off system manually.
>>
>> After this changes Its power off the board. Leaving the board with
>> solid red led blowing.
>
> You described observable issue, which is nice, but I am asking for
> technical details. What exactly do you want to achieve here?
> Technically. What is expected behaviour. In technical details, not
> only observable. I am asking for these technical details not only
> because they are important but also because I do not know them.
>
>>
>>> 3. How this relates to PWRHOLD coming from AP to the PMIC?
>>
>> No Idea right now about this right now. but will update you it I have
>> some thing.
>
> The PMIC receives two signals - PWREN and PWRHOLD. It seems strange
> that PMIC must override PWRHOLD... maybe there is an issue in
> mach-exynos code?
>
>>
>>> 4. Why this is needed only for this driver and only for this board (Odroid XU3)?
>>
>> Yes It could be generic not specific for the Odroid XU3 will correct
>> in next patch.
>
> Thanks,
> Best regards,
> Krzysztof

I don't have much technical knowlegde on the arch side PMIC.

Problem that I am trying to addressed is unclean shutdown. i.e. CPU is
still running in busy loop.
which leads external HDD not able to clean umount or power-off of the board.

[   27.427485] reboot: Power down
[   27.529236] Power down failed, please power off system manually.

My investigation lead to the following.
Reading the control register S2MPS11_REG_CTRL1 of s2mps11-pmic shown below.

[   27.411231] s2mps11-pmic s2mps11-pmic: reg value
16:00000000000000000000000000010000

clearing the bit of the control register S2MPS11_REG_CTRL1 which lead
to proper shutdown of board.

Please share you thought on this.

-Anand Moon
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