Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20201221172345.36976-1-kai.heng.feng@canonical.com>
In-Reply-To: <20201221172345.36976-1-kai.heng.feng@canonical.com>
From:   Kai-Heng Feng <kai.heng.feng@canonical.com>
Date:   Tue, 12 Jan 2021 00:18:23 +0800
Message-ID: <CAAd53p6Yn2n-oBVk026nf3oZ7y+_7NFtywQe3PBhTr=3Lo7-Bg@mail.gmail.com>
Subject: Re: [PATCH v2 1/2] thermal: int340x: Fix unexpected shutdown at
 critical temperature
To:     "Zhang, Rui" <rui.zhang@intel.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>, amitk@kernel.org
Cc:     Andrzej Pietrasiewicz <andrzej.p@collabora.com>,
        Matthew Garrett <mjg59@google.com>,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
        Akinobu Mita <akinobu.mita@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Andy Shevchenko <andy.shevchenko@gmail.com>,
        "open list:THERMAL" <linux-pm@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 8BIT
Precedence: bulk

On Tue, Dec 22, 2020 at 1:23 AM Kai-Heng Feng
<kai.heng.feng@canonical.com> wrote:
>
> We are seeing thermal shutdown on Intel based mobile workstations, the
> shutdown happens during the first trip handle in
> thermal_zone_device_register():
> kernel: thermal thermal_zone15: critical temperature reached (101 C), shutting down
>
> However, we shouldn't do a thermal shutdown here, since
> 1) We may want to use a dedicated daemon, Intel's thermald in this case,
> to handle thermal shutdown.
>
> 2) For ACPI based system, _CRT doesn't mean shutdown unless it's inside
> ThermalZone namespace. ACPI Spec, 11.4.4 _CRT (Critical Temperature):
> "... If this object it present under a device, the device’s driver
> evaluates this object to determine the device’s critical cooling
> temperature trip point. This value may then be used by the device’s
> driver to program an internal device temperature sensor trip point."
>
> So a "critical trip" here merely means we should take a more aggressive
> cooling method.
>
> As int340x device isn't present under ACPI ThermalZone, override the
> default .critical callback to prevent surprising thermal shutdown.
>
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>

A gentle ping...

> ---
> v2:
>  - Amend subject.
>  - Remove int3400 device.
>
>  .../thermal/intel/int340x_thermal/int340x_thermal_zone.c    | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c b/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c
> index 6e479deff76b..d1248ba943a4 100644
> --- a/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c
> +++ b/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c
> @@ -146,12 +146,18 @@ static int int340x_thermal_get_trip_hyst(struct thermal_zone_device *zone,
>         return 0;
>  }
>
> +static void int340x_thermal_critical(struct thermal_zone_device *zone)
> +{
> +       dev_dbg(&zone->device, "%s: critical temperature reached\n", zone->type);
> +}
> +
>  static struct thermal_zone_device_ops int340x_thermal_zone_ops = {
>         .get_temp       = int340x_thermal_get_zone_temp,
>         .get_trip_temp  = int340x_thermal_get_trip_temp,
>         .get_trip_type  = int340x_thermal_get_trip_type,
>         .set_trip_temp  = int340x_thermal_set_trip_temp,
>         .get_trip_hyst =  int340x_thermal_get_trip_hyst,
> +       .critical       = int340x_thermal_critical,
>  };
>
>  static int int340x_thermal_get_trip_config(acpi_handle handle, char *name,
> --
> 2.29.2
>