Date:   Tue, 24 Jan 2023 12:50:27 +0100
From:   Miquel Raynal <miquel.raynal@bootlin.com>
To:     Daniel Lezcano <daniel.lezcano@linaro.org>
Cc:     rafael@kernel.org, Amit Kucheria <amitk@kernel.org>,
        Zhang Rui <rui.zhang@intel.com>,
        "open list:THERMAL" <linux-pm@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] thermal/drivers/armada: Use the
 thermal_zone_get_crit_temp()
Message-ID: <20230124125027.2dba0f1a@xps-13>
In-Reply-To: <4225f833-0f15-5780-5ef4-4cd9e05eca70@linaro.org>
References: <20230118222610.186088-1-daniel.lezcano@linaro.org>
        <20230124120458.412fc528@xps-13>
        <4225f833-0f15-5780-5ef4-4cd9e05eca70@linaro.org>
Organization: Bootlin
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Precedence: bulk

Hi Daniel,

daniel.lezcano@linaro.org wrote on Tue, 24 Jan 2023 12:36:22 +0100:

> On 24/01/2023 12:04, Miquel Raynal wrote:
> > Hi Daniel,
> >=20
> > daniel.lezcano@linaro.org wrote on Wed, 18 Jan 2023 23:26:10 +0100:
> >  =20
> >> The driver browses the trip point to find out the critical trip
> >> temperature. However the function thermal_zone_get_crit_temp() does
> >> already that, so the routine is pointless in the driver.
> >>
> >> Use thermal_zone_get_crit_temp() instead of inspecting all the trip
> >> points.
> >>
> >> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> >> ---
> >>   drivers/thermal/armada_thermal.c | 38 +++++++++++++-----------------=
--
> >>   1 file changed, 15 insertions(+), 23 deletions(-)
> >>
> >> diff --git a/drivers/thermal/armada_thermal.c b/drivers/thermal/armada=
_thermal.c
> >> index db040dbdaa0a..c6d51d8acbf0 100644
> >> --- a/drivers/thermal/armada_thermal.c
> >> +++ b/drivers/thermal/armada_thermal.c
> >> @@ -784,34 +784,26 @@ static int armada_configure_overheat_int(struct =
armada_thermal_priv *priv,
> >>   					 int sensor_id)
> >>   {
> >>   	/* Retrieve the critical trip point to enable the overheat interrup=
t */
> >> -	struct thermal_trip trip;
> >> +	int temperature;
> >>   	int ret;
> >> -	int i;
> >> -
> >> -	for (i =3D 0; i < thermal_zone_get_num_trips(tz); i++) {
> >> -
> >> -		ret =3D thermal_zone_get_trip(tz, i, &trip);
> >> -		if (ret)
> >> -			return ret;
> >> -
> >> -		if (trip.type !=3D THERMAL_TRIP_CRITICAL)
> >> -			continue;
> >> -
> >> -		ret =3D armada_select_channel(priv, sensor_id);
> >> -		if (ret)
> >> -			return ret; =20
> >>   >> -		armada_set_overheat_thresholds(priv, trip.temperature, =20
> >> -					       trip.hysteresis);
> >> -		priv->overheat_sensor =3D tz;
> >> -		priv->interrupt_source =3D sensor_id;
> >> +	ret =3D thermal_zone_get_crit_temp(tz, &temperature);
> >> +	if (ret)
> >> +		return ret; =20
> >>   >> -		armada_enable_overheat_interrupt(priv); =20
> >> +	ret =3D armada_select_channel(priv, sensor_id);
> >> +	if (ret)
> >> +		return ret; =20
> >>   >> -		return 0; =20
> >> -	}
> >> +	/*
> >> +	 * A critical temperature does not have a hysteresis
> >> +	 */ =20
> >=20
> > Makes sense.
> >=20
> > Nit: I would actually put that comment in the commit log rather than
> > keeping it in the code, but whatever, that's a nice simplification. =20
>=20
> Oh, actually, I added the comment because of the third parameter change f=
or armada_set_overheat_thresholds(..., 0);

Yes, that's why I proposed to mention it in the commit log rather than
in the code. If having no threshold here makes sense (and it does), I
don't see the point in explaining it in a comment. I usually use
comments to explain what could appear strange/unclear when looking at
the code.

Here, while the parameter change is intended and legitimate, I feel
like it is worth justifying, but doing so in the commit logs feels
enough.

But that's minor tbh, so feel free to do it like you prefer.

> >> +	armada_set_overheat_thresholds(priv, temperature, 0); =20
>=20
> I think it makes sense to keep the comment to clarify why we pass this ze=
ro temperature argument.

Thanks,
Miqu=C3=A8l