linux-kernel - Re: [PATCH v3 2/2] thermal: trip: Rework thermal_zone_set

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Message-ID: <7cdce766-7bec-4654-9727-2313b466b14d@arm.com>
Date:   Wed, 29 Nov 2023 21:43:30 +0000
From:   Lukasz Luba <lukasz.luba@....com>
To:     "Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
        Zhang Rui <rui.zhang@...el.com>,
        Linux PM <linux-pm@...r.kernel.org>
Subject: Re: [PATCH v3 2/2] thermal: trip: Rework thermal_zone_set_trip() and
 its callers



On 11/29/23 13:38, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> 
> Both trip_point_temp_store() and trip_point_hyst_store() use
> thermal_zone_set_trip() to update a given trip point, but none of them
> actually needs to change more than one field in struct thermal_trip
> representing it.  However, each of them effectively calls
> __thermal_zone_get_trip() twice in a row for the same trip index value,
> once directly and once via thermal_zone_set_trip(), which is not
> particularly efficient, and the way in which thermal_zone_set_trip()
> carries out the update is not particularly straightforward.
> 
> Moreover, some checks done by them both need not go under the thermal
> zone lock and code duplication between them can be reduced quite a bit
> by moving the majority of logic into thermal_zone_set_trip().
> 
> Rework all of the above functions to address the above.
> 
> No intentional functional impact.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> ---
> 
> v2 -> v3: Fix missing return statement in thermal_zone_set_trip() (Lukasz).
> 
> v1 -> v2:
>     * Fix 2 typos in the changelog (Lukasz).
>     * Split one change into the [1/2].
> 
> ---
>   drivers/thermal/thermal_core.h  |    9 ++++++
>   drivers/thermal/thermal_sysfs.c |   52 ++++++++--------------------------
>   drivers/thermal/thermal_trip.c  |   60 +++++++++++++++++++++++++++-------------
>   include/linux/thermal.h         |    3 --
>   4 files changed, 62 insertions(+), 62 deletions(-)
> 

That looks OK. I have also checked those places
were we set the callbacks. In mainline we only use
set_trip_temp() callback. I don't know what is
Daniel's idea for the patch, but LGTM.

Reviewed-by: Lukasz Luba <lukasz.luba@....com>

also tested both patches on two arm32, arm64 boards

Tested-by: Lukasz Luba <lukasz.luba@....com>