linux-kernel - Re: [PATCH v6 4/6] mfd: tps65219: Add driver for TI TPS65219 PMIC

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Date:   Thu, 10 Nov 2022 12:16:27 -0800
From:   Kevin Hilman <khilman@...libre.com>
To:     Andrew Davis <afd@...com>, jerome Neanne <jneanne@...libre.com>,
        Nishanth Menon <nm@...com>
Cc:     Lee Jones <lee@...nel.org>, lgirdwood@...il.com,
        broonie@...nel.org, robh+dt@...nel.org, kristo@...nel.org,
        dmitry.torokhov@...il.com, krzysztof.kozlowski+dt@...aro.org,
        catalin.marinas@....com, will@...nel.org, tony@...mide.com,
        vigneshr@...com, bjorn.andersson@...aro.org, shawnguo@...nel.org,
        geert+renesas@...der.be, dmitry.baryshkov@...aro.org,
        marcel.ziswiler@...adex.com, vkoul@...nel.org,
        biju.das.jz@...renesas.com, arnd@...db.de, jeff@...undy.com,
        narmstrong@...libre.com, msp@...libre.com, j-keerthy@...com,
        linux-kernel@...r.kernel.org, devicetree@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-input@...r.kernel.org,
        linux-omap@...r.kernel.org
Subject: Re: [PATCH v6 4/6] mfd: tps65219: Add driver for TI TPS65219 PMIC

Andrew Davis <afd@...com> writes:

> On 11/10/22 11:00 AM, Kevin Hilman wrote:
>> jerome Neanne <jneanne@...libre.com> writes:
>> 
>>> On 09/11/2022 22:59, Andrew Davis wrote:
>>>> On 11/7/22 3:14 PM, Kevin Hilman wrote:
>>>>> Nishanth Menon <nm@...com> writes:
>>>>>
>>>>>> On 13:58-20221104, jerome Neanne wrote:
>>>>>>>
>>>>>> [...]
>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>> Can you try an compile with W=1 please.
>>>>>>> This raise one warning on mfd:
>>>>>>> drivers/mfd/tps65219.c:28:12: warning: ‘tps65219_soft_shutdown’
>>>>>>> defined but
>>>>>>> not used [-Wunused-function]
>>>>>>>      28 | static int tps65219_soft_shutdown(struct tps65219 *tps)
>>>>>>>         |            ^~~~~~~~~~~~~~~~~~~~~~
>>>>>>> soft_shutdown has been validated and is used in TI baseline even if not
>>>>>>> hooked in upstream version further to this review:
>>>>>>> https://lore.kernel.org/lkml/20220825150224.826258-5-msp@baylibre.com/
>>>>>>>
>>>>>>> It was a TI requirement to implement it...
>>>>>>> Let me know if you want me to remove this function or if we can keep
>>>>>>> it like
>>>>>>> this.
>>>>>>
>>>>>> There are platforms without psci, correct? I think the comment was to
>>>>>> drop the force override with system-power-controller property,
>>>>>>
>>>>>> if (!pm_power_off) {
>>>>>>      tps65219_i2c_client = client;
>>>>>>      pm_power_off = &tps65219_pm_power_off;
>>>>>> }
>>>>>>
>>>>>> Could still be valid for such platforms, no? I do see that the
>>>>>> capability that the PMIC has - which is software shutdown is a valid
>>>>>> feature that we support in many different PMIC drivers. Is'nt the job of
>>>>>> the driver to introduce the functionality in a manner that is
>>>>>> appropriate to the OS framework?
>>>>>
>>>>> Yeah, I think Nishanth is right here.
>>>>>
>>>>> We should probably keep the `if (!pm_power_off)` part so the PMIC will
>>>>> be used if PSCI is not, but it also allows an easy way to test/use the
>>>>> PMIC
>>>>> shutdown functionality downstream if needed.
>>>>>
>>>>
>>>> Then should be using the sys-off handler API[0] so it doesn't block PSCI
>>>> which is also switching over[1].
>>>>
>>>> Andrew
>>>>
>>>> [0] https://lwn.net/Articles/894511/
>>>> [1] https://www.spinics.net/lists/arm-kernel/msg1024127.html
>>> Can we go for upstream with v7 without tps65219_soft_shutdown. Then if
>>> everyone agrees with Andrew proposal, I'll submit a separate patch which
>>> adds implementation of tps65219_soft_shutdown support through sys-off
>>> handler.
>>>
>>> So that we are not blocking upstream in case further
>>> discussions/alignment are required.
>> 
>> Seems OK to me.  Nishanth?  Andrew?
>> 
>> But I think you'll need to at least submit a v8 without the unused
>> code/dead code that Lee pointed out.
>> 
>
> If you need the v8 anyway, then add support through sys-off in
> that spin, should only be a couple lines of change.

Oops, my mistake.  I see v7 already has the dead code removed.  I got
confused because this thread is on v6.

IMO, I think v7 should be merged v7 (mfd part is already ack'd by Lee)
and then Jerome will follow up with the support for sys-off as an
additional series.

Kevin