Received-SPF: pass (google.com: domain of linux-kernel+bounces-195092-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161;
Date: Thu, 30 May 2024 10:51:27 +0200
From: Johan Hovold <johan@kernel.org>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Johan Hovold <johan+linaro@kernel.org>, Lee Jones <lee@kernel.org>,
	Mark Brown <broonie@kernel.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Bjorn Andersson <andersson@kernel.org>,
	Konrad Dybcio <konrad.dybcio@linaro.org>,
	Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Liam Girdwood <lgirdwood@gmail.com>,
	Das Srinagesh <quic_gurus@quicinc.com>,
	Satya Priya Kakitapalli <quic_skakitap@quicinc.com>,
	Stephen Boyd <swboyd@chromium.org>,
	Bryan O'Donoghue <bryan.odonoghue@linaro.org>,
	linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org
Subject: Re: [PATCH v2 03/14] mfd: pm8008: deassert reset on probe
Message-ID: <Zlg-D5yfrafbUei1@hovoldconsulting.com>
References: <20240529162958.18081-1-johan+linaro@kernel.org>
 <20240529162958.18081-4-johan+linaro@kernel.org>
 <CAHp75VdnTQJFfqOdxC99gWckxebdUr4hV0wp3ZTs1Pey7q_fsA@mail.gmail.com>
 <Zlgz3nDjfRO5LYnY@hovoldconsulting.com>
 <CAHp75VewzRUiKQvQ9D9HWPOo6Yfqtv+AV+AVTPQO=foRzMoegw@mail.gmail.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <CAHp75VewzRUiKQvQ9D9HWPOo6Yfqtv+AV+AVTPQO=foRzMoegw@mail.gmail.com>

On Thu, May 30, 2024 at 11:34:55AM +0300, Andy Shevchenko wrote:
> On Thu, May 30, 2024 at 11:08 AM Johan Hovold <johan@kernel.org> wrote:
> > On Wed, May 29, 2024 at 10:45:40PM +0300, Andy Shevchenko wrote:
> > > On Wed, May 29, 2024 at 7:30 PM Johan Hovold <johan+linaro@kernel.org> wrote:
> > > >
> > > > Request and deassert any (optional) reset gpio during probe in case it
> > > > has been left asserted by the boot firmware.
> > > >
> > > > Note the reset line is not asserted to avoid reverting to the default
> > > > I2C address in case the firmware has configured an alternate address.
> 
> ...
> 
> > > > +       /*
> > > > +        * The PMIC does not appear to require a post-reset delay, but wait
> > > > +        * for a millisecond for now anyway.
> > > > +        */
> > >
> > > > +       usleep_range(1000, 2000);
> > >
> > > fsleep() ?
> >
> > No, I'd only use fsleep() when the argument is variable.
> 
> Okay, this is basically the same issue as with use of dev_err_probe()
> with known errors. fsleep() hides the choice between let's say
> msleep() / usleep_range() / udelay() from the caller. This, in
> particular, might allow shifting constraints if the timer core is
> changed or becomes more granular. It's independent to the variable or
> constant parameter(s). Whatever, I'm not going to insist.

I prefer that developers are aware of what they are doing and understand
the difference between, say, usleep_range() and udelay(), instead of
hiding things away in obscure helper functions.

Johan