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Date:   Tue, 29 Jun 2021 13:09:57 +0200
From:   Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
To:     Axel Lin <axel.lin@ingics.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linuxarm@huawei.com, mauro.chehab@huawei.com,
        Lee Jones <lee.jones@linaro.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-staging@lists.linux.dev
Subject: Re: [PATCH v10 2/5] regulator: hi6421v600-regulator: fix platform
 drvdata
Message-ID: <20210629130957.484f5c43@coco.lan>
In-Reply-To: <CAFRkauCzHqUfva+zTRhOyiMMb4WsKPHvYJuqpOPwy+siPMZGOQ@mail.gmail.com>
References: <cover.1624962269.git.mchehab+huawei@kernel.org>
        <eed34e8897c79a2ab13573d3da12c86569bca0f6.1624962269.git.mchehab+huawei@kernel.org>
        <CAFRkauCzHqUfva+zTRhOyiMMb4WsKPHvYJuqpOPwy+siPMZGOQ@mail.gmail.com>
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Em Tue, 29 Jun 2021 18:48:31 +0800
Axel Lin <axel.lin@ingics.com> escreveu:

> Mauro Carvalho Chehab <mchehab+huawei@kernel.org> =E6=96=BC 2021=E5=B9=B4=
6=E6=9C=8829=E6=97=A5 =E9=80=B1=E4=BA=8C =E4=B8=8B=E5=8D=886:31=E5=AF=AB=E9=
=81=93=EF=BC=9A
>=20
> > platform drvdata can't be used inside the regulator driver,
> > as this is already used by the MFD and SPMI drivers.
> > =20
>=20
> Could you point out which part of the code set the platform drvdata?
> My understanding is the mfd only set dev->platform_data rather than
> dev->driver_data.
> If you mean the dev_set_drvdata() call in hi6421_spmi_pmic_probe, it's the
> parent device of the regulator pdev.

It needs to be double-checked, but I guess the SPMI or the SPMI controller
driver already uses it.

See, there are 5 drivers involved, all of them using private data
and passing data to child drivers, called on the order below:

	spmi
	hisi-spmi-controller
	hi6421-spmi-pmic
	mfd drivers:
		hi6421v600-irq
		hi6421-regulator

If you're in doubt, try to apply this series, and then change the
driver again to use platform data. You'll see that it will stop
booting after initializing the first regulator.

Thanks,
Mauro