linux-kernel - Re: Applied "regulator: wm8994: Pass descriptor instead of GPIO number" to the regulator tree

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Message-ID: <772b6fdc-57af-fef2-0c85-78446bec2c2a@samsung.com>
Date:   Tue, 20 Nov 2018 17:34:51 +0100
From:   Marek Szyprowski <m.szyprowski@...sung.com>
To:     Richard Fitzgerald <rf@...nsource.cirrus.com>,
        Charles Keepax <ckeepax@...nsource.cirrus.com>
Cc:     Mark Brown <broonie@...nel.org>,
        Linus Walleij <linus.walleij@...aro.org>,
        Lee Jones <lee.jones@...aro.org>,
        Liam Girdwood <lgirdwood@...il.com>,
        linux-kernel@...r.kernel.org, patches@...nsource.cirrus.com
Subject: Re: Applied
 "regulator: wm8994: Pass descriptor instead of GPIO number" to the regulator
 tree

Hi Richard,

On 2018-11-20 17:16, Richard Fitzgerald wrote:
> On 20/11/18 15:56, Marek Szyprowski wrote:
>> Hi Charles,
>>
>> On 2018-11-20 16:36, Charles Keepax wrote:
>>> On Tue, Nov 20, 2018 at 03:32:15PM +0000, Charles Keepax wrote:
>>>> On Tue, Nov 20, 2018 at 03:58:59PM +0100, Marek Szyprowski wrote:
>>>>> On 2018-11-20 15:47, Charles Keepax wrote:
>>>>>> On Tue, Nov 20, 2018 at 02:43:32PM +0100, Marek Szyprowski wrote:
>>>>>>> On 2018-05-17 18:41, Mark Brown wrote:
>>>>>>>> Subject: [PATCH] regulator: wm8994: Pass descriptor instead of
>>>>>>>> GPIO number
>>>>>>> This patch causes following kernel warning on Samsung Exynos4412
>>>>>>> based
>>>>>>> Trats2 board:
>>>>>>>
>>>>>>> wm8994 4-001a: Failed to get supply 'DBVDD1': -517
>>>>>>> wm8994 4-001a: Failed to get supplies: -517
>>>> This is really weird, because the error in your log relates to
>>>> DBVDD1 which is an independent regulator supplied by a separate
>>>> regulator. I am really having some difficulty seeing how the
>>>> patch interfers. It is definitely that patch which causes the
>>>> issue, like you revert it and things work again?
>>> Wait does the board still boot just you have an extra probe defer
>>> now? Or does it actually fail?
>>
>> The board boots fine. The only new thing is the mentioned warning, which
>> I would
>>
>> like to have fixed.
>>
>>
>> Best regards
>>
>
> -517 is EPROBE_DEFER. This isn't something  that needs "fixing" unless
> the
> driver is never able to probe.
>
> If the wm8994 eventually probes ok after retries it's not a problem,
> it's normal kernel behaviour.
>
> If the wm8994 driver never manages to probe successfully it should
> mean that
> the driver which supplies DBVDD1 isn't available.

Deferred probe was there already. This patch however introduced the
warning from gpiolib and I would like to have it fixed somehow. In both
cases (with this patch and before it) the wm8994 driver probes okay -
when the required regulators are finally available.

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland