Received-SPF: pass (google.com: domain of linux-kernel+bounces-58272-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Precedence: bulk
MIME-Version: 1.0
References: <2731410.mvXUDI8C0e@kreacher> <b068b36a-9964-4d32-bb00-227893f9e47e@linaro.org>
In-Reply-To: <b068b36a-9964-4d32-bb00-227893f9e47e@linaro.org>
From: "Rafael J. Wysocki" <rafael@kernel.org>
Date: Thu, 8 Feb 2024 16:15:04 +0100
Message-ID: <CAJZ5v0jPiHkxL1a7DFU6Km9694PQCwnnk7sRm=mmz1uxhdoNVg@mail.gmail.com>
Subject: Re: [PATCH v2] thermal: sysfs: Make trip hysteresis writable along
 with trip temperature
To: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>, Linux PM <linux-pm@vger.kernel.org>, 
	LKML <linux-kernel@vger.kernel.org>, Lukasz Luba <lukasz.luba@arm.com>, 
	Zhang Rui <rui.zhang@intel.com>, 
	Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>, 
	Manaf Meethalavalappu Pallikunhi <quic_manafm@quicinc.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

On Thu, Feb 8, 2024 at 3:42=E2=80=AFPM Daniel Lezcano <daniel.lezcano@linar=
o.org> wrote:
>
> On 31/01/2024 19:44, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> >
> > Trip point temperature can be modified via sysfs if
> > CONFIG_THERMAL_WRITABLE_TRIPS is enabled and the thermal
> > zone creator requested that the given trip be writable
> > in the writable trips mask passed to the registration
> > function.
> >
> > However, trip point hysteresis is treated differently - it is only
> > writable if the thermal zone has a .set_trip_hyst() operation defined
> > and neither CONFIG_THERMAL_WRITABLE_TRIPS, nor the writable trips mask
> > supplied by the zone creator has any bearing on this.  That is
> > inconsistent and confusing, and it generally does not meet user
> > expectations.
> >
> > For this reason, modify create_trip_attrs() to handle trip point
> > hysteresis in the same way as trip point temperature, so they both
> > are writable at the same time regardless of what trip point operations
> > are defined for the thermal zone.
> >
> > Link: https://lore.kernel.org/linux-pm/20240106191502.29126-1-quic_mana=
fm@quicinc.com
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > ---
>
> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Thanks, but I need to withdraw this one, because there are drivers
that actively don't want their trip points' hysteresis to be adjusted
via sysfs, so I'm now working on a patch series that will tackle this
in a more systematic way.