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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Thu, 7 Nov 2019 09:30:36 +0100
Message-ID: <CAMuHMdXSKU40E8Br0Z53H2FyrQsLxnB-EERZoN6HQHExP5tqxQ@mail.gmail.com>
Subject: Re: [PATCH] mmc: renesas_sdhi: add checks for pinctrl_lookup_state
To:     Wolfram Sang <wsa@the-dreams.de>
Cc:     Ulf Hansson <ulf.hansson@linaro.org>,
        Chuhong Yuan <hslester96@gmail.com>,
        Wolfram Sang <wsa+renesas@sang-engineering.com>,
        "linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Hi Wolfram,

On Thu, Oct 31, 2019 at 11:58 PM Wolfram Sang <wsa@the-dreams.de> wrote:
> > > Well, I don't like to bail out because this error is not fatal for basic
> > > operations. How about releasing priv->pinctrl again with an additional
> > > warning that pinctrl settings are broken and will prevent 1.8v modes?
> > >
> > > Opinions?
> >
> > Hmm, from a mmc driver probe point of view, I don't quite share this approach.
> >
> > I would rather fail as it forces the DTB to be corrected immediately,
> > rather than trusting some developer to look at a warning in a log. The
> > point is, in such a case it may never get fixed, if the product is
> > shipped with the wrong DTB.
>
> I could agree to this arguement, iff the only way pinctrl_select fails
> is a DT misconfiguration. I am not sure if this is true right now, and
> we can't be sure about the future. Or?

Isn't "state_uhs" optional? So bailing out if it doesn't exist is wrong.
"default" should be there, if the device node has pinctrl properties.

renesas_sdhi_start_signal_voltage_switch() already handles fallback
to 3v3 operation.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds