From: Mikko Perttunen <[email protected]>
Thermal zones located in power domains may not be accessible when
the domain is powergated. In this situation, reading the temperature
will return -BPMP_EFAULT and the temperature is considered to be
-256C for calculating trips.
For smooth operation, for offline zones, return -EAGAIN when reading
the temperature and allow registration of zones even if they are
offline during probe.
Signed-off-by: Mikko Perttunen <[email protected]>
---
drivers/thermal/tegra/tegra-bpmp-thermal.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/thermal/tegra/tegra-bpmp-thermal.c b/drivers/thermal/tegra/tegra-bpmp-thermal.c
index c76e1ea62c8a..628b18818ae9 100644
--- a/drivers/thermal/tegra/tegra-bpmp-thermal.c
+++ b/drivers/thermal/tegra/tegra-bpmp-thermal.c
@@ -52,6 +52,8 @@ static int __tegra_bpmp_thermal_get_temp(struct tegra_bpmp_thermal_zone *zone,
err = tegra_bpmp_transfer(zone->tegra->bpmp, &msg);
if (err)
return err;
+ if (msg.rx.ret == -BPMP_EFAULT)
+ return -EAGAIN;
if (msg.rx.ret)
return -EINVAL;
@@ -257,7 +259,12 @@ static int tegra_bpmp_thermal_probe(struct platform_device *pdev)
zone->tegra = tegra;
err = __tegra_bpmp_thermal_get_temp(zone, &temp);
- if (err < 0) {
+
+ /*
+ * Sensors in powergated domains may temporarily fail to be read
+ * (-EAGAIN), but will become accessible when the domain is powered on.
+ */
+ if (err < 0 && err != -EAGAIN) {
devm_kfree(&pdev->dev, zone);
continue;
}
--
2.39.0
On Tue, Feb 07, 2023 at 03:56:08PM +0200, Mikko Perttunen wrote:
> From: Mikko Perttunen <[email protected]>
>
> Thermal zones located in power domains may not be accessible when
> the domain is powergated. In this situation, reading the temperature
> will return -BPMP_EFAULT and the temperature is considered to be
> -256C for calculating trips.
Where's that -256C being set? I only see THERMAL_TEMP_INVALID being set
as the default for a zone, but that's not -274C, not -256C. If that's
the temperature that you're referring to, it might be better to state
that we rely on the default temperature rather than any specific number.
Thierry
>
> For smooth operation, for offline zones, return -EAGAIN when reading
> the temperature and allow registration of zones even if they are
> offline during probe.
>
> Signed-off-by: Mikko Perttunen <[email protected]>
> ---
> drivers/thermal/tegra/tegra-bpmp-thermal.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/thermal/tegra/tegra-bpmp-thermal.c b/drivers/thermal/tegra/tegra-bpmp-thermal.c
> index c76e1ea62c8a..628b18818ae9 100644
> --- a/drivers/thermal/tegra/tegra-bpmp-thermal.c
> +++ b/drivers/thermal/tegra/tegra-bpmp-thermal.c
> @@ -52,6 +52,8 @@ static int __tegra_bpmp_thermal_get_temp(struct tegra_bpmp_thermal_zone *zone,
> err = tegra_bpmp_transfer(zone->tegra->bpmp, &msg);
> if (err)
> return err;
> + if (msg.rx.ret == -BPMP_EFAULT)
> + return -EAGAIN;
> if (msg.rx.ret)
> return -EINVAL;
>
> @@ -257,7 +259,12 @@ static int tegra_bpmp_thermal_probe(struct platform_device *pdev)
> zone->tegra = tegra;
>
> err = __tegra_bpmp_thermal_get_temp(zone, &temp);
> - if (err < 0) {
> +
> + /*
> + * Sensors in powergated domains may temporarily fail to be read
> + * (-EAGAIN), but will become accessible when the domain is powered on.
> + */
> + if (err < 0 && err != -EAGAIN) {
> devm_kfree(&pdev->dev, zone);
> continue;
> }
> --
> 2.39.0
>
On 2/8/23 12:31, Thierry Reding wrote:
> On Tue, Feb 07, 2023 at 03:56:08PM +0200, Mikko Perttunen wrote:
>> From: Mikko Perttunen <[email protected]>
>>
>> Thermal zones located in power domains may not be accessible when
>> the domain is powergated. In this situation, reading the temperature
>> will return -BPMP_EFAULT and the temperature is considered to be
>> -256C for calculating trips.
>
> Where's that -256C being set? I only see THERMAL_TEMP_INVALID being set
> as the default for a zone, but that's not -274C, not -256C. If that's
> the temperature that you're referring to, it might be better to state
> that we rely on the default temperature rather than any specific number.
>
> Thierry
It is based on BPMP's internal behavior.
Mikko
>
>>
>> For smooth operation, for offline zones, return -EAGAIN when reading
>> the temperature and allow registration of zones even if they are
>> offline during probe.
>>
>> Signed-off-by: Mikko Perttunen <[email protected]>
>> ---
>> drivers/thermal/tegra/tegra-bpmp-thermal.c | 9 ++++++++-
>> 1 file changed, 8 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/thermal/tegra/tegra-bpmp-thermal.c b/drivers/thermal/tegra/tegra-bpmp-thermal.c
>> index c76e1ea62c8a..628b18818ae9 100644
>> --- a/drivers/thermal/tegra/tegra-bpmp-thermal.c
>> +++ b/drivers/thermal/tegra/tegra-bpmp-thermal.c
>> @@ -52,6 +52,8 @@ static int __tegra_bpmp_thermal_get_temp(struct tegra_bpmp_thermal_zone *zone,
>> err = tegra_bpmp_transfer(zone->tegra->bpmp, &msg);
>> if (err)
>> return err;
>> + if (msg.rx.ret == -BPMP_EFAULT)
>> + return -EAGAIN;
>> if (msg.rx.ret)
>> return -EINVAL;
>>
>> @@ -257,7 +259,12 @@ static int tegra_bpmp_thermal_probe(struct platform_device *pdev)
>> zone->tegra = tegra;
>>
>> err = __tegra_bpmp_thermal_get_temp(zone, &temp);
>> - if (err < 0) {
>> +
>> + /*
>> + * Sensors in powergated domains may temporarily fail to be read
>> + * (-EAGAIN), but will become accessible when the domain is powered on.
>> + */
>> + if (err < 0 && err != -EAGAIN) {
>> devm_kfree(&pdev->dev, zone);
>> continue;
>> }
>> --
>> 2.39.0
>>
On Wed, Feb 08, 2023 at 05:35:48PM +0200, Mikko Perttunen wrote:
> On 2/8/23 12:31, Thierry Reding wrote:
> > On Tue, Feb 07, 2023 at 03:56:08PM +0200, Mikko Perttunen wrote:
> > > From: Mikko Perttunen <[email protected]>
> > >
> > > Thermal zones located in power domains may not be accessible when
> > > the domain is powergated. In this situation, reading the temperature
> > > will return -BPMP_EFAULT and the temperature is considered to be
> > > -256C for calculating trips.
> >
> > Where's that -256C being set? I only see THERMAL_TEMP_INVALID being set
> > as the default for a zone, but that's not -274C, not -256C. If that's
> > the temperature that you're referring to, it might be better to state
> > that we rely on the default temperature rather than any specific number.
> >
> > Thierry
>
> It is based on BPMP's internal behavior.
Okay, maybe clarify that part of the sentence then. Could be something
like:
... will return -BPMP_EFAULT. When evaluating trips, BPMP will
internally use -256C as the temperature for offline zones.
Thierry