linux-kernel - Re: [PATCH v2 2/9] i2c: riic: Use local `dev` pointer in `dev_err

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Message-ID: <CA+V-a8sDRLNY1cTuoG4oJSBu+97Ri6qON8RRc_AeDO2Z_bz=9Q@mail.gmail.com>
Date: Thu, 26 Dec 2024 07:39:33 +0000
From: "Lad, Prabhakar" <prabhakar.csengg@...il.com>
To: Andi Shyti <andi.shyti@...nel.org>
Cc: Chris Brandt <chris.brandt@...esas.com>, Philipp Zabel <p.zabel@...gutronix.de>, 
	Wolfram Sang <wsa@...nel.org>, Geert Uytterhoeven <geert+renesas@...der.be>, 
	linux-renesas-soc@...r.kernel.org, linux-i2c@...r.kernel.org, 
	linux-kernel@...r.kernel.org, Biju Das <biju.das.jz@...renesas.com>, 
	Fabrizio Castro <fabrizio.castro.jz@...esas.com>, 
	Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
Subject: Re: [PATCH v2 2/9] i2c: riic: Use local `dev` pointer in `dev_err_probe()`

Hi Andi,

On Thu, Dec 26, 2024 at 1:19 AM Andi Shyti <andi.shyti@...nel.org> wrote:
>
> Hi Prabhakar,
>
> On Wed, Dec 18, 2024 at 12:16:11AM +0000, Prabhakar wrote:
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
> >
> > Update the `riic_init_hw()` function to use the local `dev` pointer in
> > calls to `dev_err_probe()`. Previously, `riic_init_hw()` used
> > `riic->adapter.dev` in error reporting. Since this function is invoked
> > during the probe phase, the I2C adapter is not yet initialized, leading to
> > `(null) ...` being printed in error messages. This patch fixes the issue by
> > consistently using the local `dev` pointer, which points to
> > `riic->adapter.dev.parent`.
> >
> > Additionally, replace `dev_err()` with `dev_err_probe()` throughout
> > `riic_init_hw()` for consistency.
> >
> > Fixes: d982d66514192 ("i2c: riic: remove clock and frequency restrictions")
> > Fixes: 71dacb2565ed (i2c: riic: Simplify unsupported bus speed handling")
>
> I'm not sure the Fixes are really necessary here, as it's not
> really leading to a bug, but I can live with it. But, then, ...
>
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@...renesas.com>
> > Reviewed-by: Geert Uytterhoeven <geert+renesas@...der.be>
> > ---
> > v1->v2
> > - Collected RB tag from Geert
> > ---
> >  drivers/i2c/busses/i2c-riic.c | 10 ++++------
> >  1 file changed, 4 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c
> > index bfaa2d728a76..01195ffd4c07 100644
> > --- a/drivers/i2c/busses/i2c-riic.c
> > +++ b/drivers/i2c/busses/i2c-riic.c
> > @@ -320,7 +320,7 @@ static int riic_init_hw(struct riic_dev *riic)
> >                                     : I2C_MAX_FAST_MODE_FREQ;
> >
> >       if (t->bus_freq_hz > max_freq)
> > -             return dev_err_probe(&riic->adapter.dev, -EINVAL,
> > +             return dev_err_probe(dev, -EINVAL,
> >                                    "unsupported bus speed %uHz (%u max)\n",
> >                                    t->bus_freq_hz, max_freq);
> >
> > @@ -356,11 +356,9 @@ static int riic_init_hw(struct riic_dev *riic)
> >               rate /= 2;
> >       }
> >
> > -     if (brl > (0x1F + 3)) {
> > -             dev_err(&riic->adapter.dev, "invalid speed (%lu). Too slow.\n",
> > -                     (unsigned long)t->bus_freq_hz);
> > -             return -EINVAL;
> > -     }
> > +     if (brl > (0x1F + 3))
> > +             return dev_err_probe(dev, -EINVAL, "invalid speed (%lu). Too slow.\n",
> > +                                  (unsigned long)t->bus_freq_hz);
>
> ... I'm not happy with the splitting here: mixing a bug fix with
> a cosmetic is wrong for two reasons:
>
>  - they are conceptually different;
>  - fixes take are applied to the -fixes branch and sent to the
>    weekly pull request.
>
> I will appreciate if this second chunk is squashed with patch 1
> and the first part has a patch on its own.
>
OK, I think the best approach here would be to promote this to patch
#1 ie just replacing `&riic->adapter.dev` with `dev` (as second chunk
also includes the fix along with cosmetic change) and then make patch
#2 as replacing `dev_err` with `dev_err_probe`.

Please let me know if this is OK with you.

Cheers,
Prabhakar