linux-kernel - Re: [PATCH] drivers: thermal: tsens: respect thermal_device

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Date:   Wed, 19 Jan 2022 16:33:57 -0800
From:   Bjorn Andersson <bjorn.andersson@...aro.org>
To:     Benjamin Li <benl@...areup.com>
Cc:     Amit Kucheria <amitk@...nel.org>,
        Thara Gopinath <thara.gopinath@...aro.org>,
        Andy Gross <agross@...nel.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Zhang Rui <rui.zhang@...el.com>, linux-pm@...r.kernel.org,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] drivers: thermal: tsens: respect thermal_device_mode in
 threshold irq reporting

On Thu 13 Jan 19:13 PST 2022, Benjamin Li wrote:

> 'echo disabled > .../thermal_zoneX/mode' will disable the thermal core's
> polling mechanism to check for threshold trips. However, tsens supports
> an interrupt mechanism to receive notification of trips, implemented in
> commit 634e11d5b450 ("drivers: thermal: tsens: Add interrupt support").
> This is used sometimes to run performance test cases.
> 
> Currently the thermal zone mode that's set by userspace is not checked
> before propagating threshold trip events from IRQs. Let's fix this to
> restore the abilty to disable thermal throttling at runtime.
> 
> ====================
> 
> Tested on MSM8939 running 5.16.0. This platform has 8 cores; the first
> four thermal zones control cpu0-3 and the last zone is for the other four
> CPUs together.
> 
>   for f in /sys/class/thermal/thermal_zone*; do
>     echo "disabled" > $f/mode
>     echo $f | paste - $f/type $f/mode
>   done
> 
> /sys/class/thermal/thermal_zone0	cpu0-thermal	disabled
> /sys/class/thermal/thermal_zone1	cpu1-thermal	disabled
> /sys/class/thermal/thermal_zone2	cpu2-thermal	disabled
> /sys/class/thermal/thermal_zone3	cpu3-thermal	disabled
> /sys/class/thermal/thermal_zone4	cpu4567-thermal	disabled
> 
> With mitigation thresholds at 75 degC and load running, we can now cruise
> past temp=75000 without CPU throttling kicking in.
> 
>   watch -n 1 "grep '' /sys/class/thermal/*/temp
>       /sys/class/thermal/*/cur_state
>       /sys/bus/cpu/devices/cpu*/cpufreq/cpuinfo_cur_freq"
> 
> /sys/class/thermal/thermal_zone0/temp:82000
> /sys/class/thermal/thermal_zone1/temp:84000
> /sys/class/thermal/thermal_zone2/temp:87000
> /sys/class/thermal/thermal_zone3/temp:84000
> /sys/class/thermal/thermal_zone4/temp:84000
> /sys/class/thermal/cooling_device0/cur_state:0
> /sys/class/thermal/cooling_device1/cur_state:0
> /sys/bus/cpu/devices/cpu0/cpufreq/cpuinfo_cur_freq:1113600
> /sys/bus/cpu/devices/cpu1/cpufreq/cpuinfo_cur_freq:1113600
> /sys/bus/cpu/devices/cpu2/cpufreq/cpuinfo_cur_freq:1113600
> /sys/bus/cpu/devices/cpu3/cpufreq/cpuinfo_cur_freq:1113600
> /sys/bus/cpu/devices/cpu4/cpufreq/cpuinfo_cur_freq:800000
> /sys/bus/cpu/devices/cpu5/cpufreq/cpuinfo_cur_freq:800000
> /sys/bus/cpu/devices/cpu6/cpufreq/cpuinfo_cur_freq:800000
> /sys/bus/cpu/devices/cpu7/cpufreq/cpuinfo_cur_freq:800000
> 
> Reported-by: Zac Crosby <zac@...areup.com>
> Signed-off-by: Benjamin Li <benl@...areup.com>

Reviewed-by: Bjorn Andersson <bjorn.andersson@...aro.org>

Regards,
Bjorn

> ---
>  drivers/thermal/qcom/tsens.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/thermal/qcom/tsens.c b/drivers/thermal/qcom/tsens.c
> index 99a8d9f3e03c..0b6299512e7c 100644
> --- a/drivers/thermal/qcom/tsens.c
> +++ b/drivers/thermal/qcom/tsens.c
> @@ -509,13 +509,16 @@ static irqreturn_t tsens_irq_thread(int irq, void *data)
>  		spin_unlock_irqrestore(&priv->ul_lock, flags);
>  
>  		if (trigger) {
> -			dev_dbg(priv->dev, "[%u] %s: TZ update trigger (%d mC)\n",
> -				hw_id, __func__, temp);
> -			thermal_zone_device_update(s->tzd,
> -						   THERMAL_EVENT_UNSPECIFIED);
> +			if (s->tzd->mode == THERMAL_DEVICE_ENABLED) {
> +				dev_dbg(priv->dev, "[%u] %s: TZ update trigger (%d mC)\n",
> +					hw_id, __func__, temp);
> +				thermal_zone_device_update(s->tzd, THERMAL_EVENT_UNSPECIFIED);
> +			} else {
> +				dev_dbg(priv->dev, "[%u] %s: TZ update trigger (%d mC) skipped as zone disabled\n",
> +					hw_id, __func__, temp);
> +			}
>  		} else {
> -			dev_dbg(priv->dev, "[%u] %s: no violation:  %d\n",
> -				hw_id, __func__, temp);
> +			dev_dbg(priv->dev, "[%u] %s: no violation:  %d\n", hw_id, __func__, temp);
>  		}
>  
>  		if (tsens_version(priv) < VER_0_1) {
> -- 
> 2.17.1
>