linux-kernel - Re: [PATCH v1 3/3] iio: imu: adis16480: Fix getting the optional clocks

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Date:   Thu, 14 Apr 2022 15:48:42 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Nuno Sá <noname.nuno@...il.com>
Cc:     "Sa, Nuno" <Nuno.Sa@...log.com>,
        "linux-iio@...r.kernel.org" <linux-iio@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Lars-Peter Clausen <lars@...afoo.de>,
        "Hennerich, Michael" <Michael.Hennerich@...log.com>,
        Jonathan Cameron <jic23@...nel.org>
Subject: Re: [PATCH v1 3/3] iio: imu: adis16480: Fix getting the optional
 clocks

On Thu, Apr 14, 2022 at 09:07:29AM +0200, Nuno Sá wrote:
> On Wed, 2022-04-13 at 19:58 +0300, Andy Shevchenko wrote:
> > On Wed, Apr 13, 2022 at 03:38:47PM +0000, Sa, Nuno wrote:
> > > > From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> > > > Sent: Wednesday, April 13, 2022 4:41 PM
> > 
> > > > The extended clocks are optional and may not be present for some
> > > > SoCs
> > > > supported by this driver. Nevertheless, in case the clock is
> > > > provided
> > > > but some error happens during its getting, that error should be
> > > > handled
> > > > properly. Use devm_clk_get_optional() API for that. Also report
> > > > possible
> > > > errors using dev_err_probe() to handle properly -EPROBE_DEFER
> > > > error.
> > 
> > > This is a nice cleanup patch... But the subject might be a bit
> > > misleading as it says "Fix". So I would expect a Fixes tag which
> > > I'm not sure it's really worth it here. Yes, the code was pretty
> > > much
> > > doing clk_get_optional() "by hand" but I think it was still
> > > functional.
> > > So to me, this is more an improvement rather than a fix...
> > 
> > Actually it is a fix, but not critical since no-one complains aloud
> > so far.
> > The problematic part is logs exhausting if repetitive deferred probe
> > happens.
> 
> Still not really agree with it... In the commit message you state that
> errors are not properly handled and so let's use
> 'devm_clk_get_optional()'. I don't think that is true because If im not
> missing nothing there's no fundamental change between the previous code
> and using 'devm_clk_get_optional()'. So to me this is an enhancement
> because we were doing something "by hand" when we have an API for it.
> 
> That said, introducing dev_err_probe() indeed stops possibly annoying
> error messages for EPROBE_DEFER (and that could be seen as a fix, not
> really devm_clk_get_optional()). I honestly still don't see it as fix
> but we are also not adding a Fixes tag so I don't really care :).
> 
> (But I still think the commit message is a bit misleading)

Yes, the commit message can be amended. I won't split these two since
the fix part is not critical (nobody so far complained aloud about it).
That's why I prefer to set the main point of the change as switching to
devm_clk_get_optional() than deferred probe messages.

-- 
With Best Regards,
Andy Shevchenko