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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <dpx4cpffb3mfh5i4w2gahjxpswjyxnl6nixwkl5xzkoas77uvf@yrdiivu36szx>
Date: Thu, 26 Dec 2024 11:06:05 +0100
From: Andi Shyti <andi.shyti@...nel.org>
To: "Lad, Prabhakar" <prabhakar.csengg@...il.com>
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,

On Thu, Dec 26, 2024 at 07:39:33AM +0000, Lad, Prabhakar wrote:
> On Thu, Dec 26, 2024 at 1:19 AM Andi Shyti <andi.shyti@...nel.org> wrote:
> > 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, ...

On a second thought, I think this Fixes tag is not needed: there
is no bug as the missing reference is already handled.

> > > 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.

As Wolfram suggested, the dev_err_probe chunk can be squashed in
the patch 1 and make a single patch that is about
/dev_err/dev_err_probe. Further splitting based on internal
functions is a bit too much.

While the first chunk belongs to a different change.

Please, keep all the tags in your next version: I don't believe
anyone would object.

Thanks,
Andi