diff mbox series

[v13,02/35] soc/tegra: Add devm_tegra_core_dev_init_opp_table_common()

Message ID 20210926224058.1252-3-digetx@gmail.com (mailing list archive)
State Not Applicable, archived
Headers show
Series NVIDIA Tegra power management patches for 5.16 | expand

Commit Message

Dmitry Osipenko Sept. 26, 2021, 10:40 p.m. UTC
Only couple drivers need to get the -ENODEV error code and majority of
drivers need to explicitly initialize the performance state. Add new
common helper which sets up OPP table for these drivers.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 include/soc/tegra/common.h | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

Comments

Ulf Hansson Oct. 1, 2021, 12:50 p.m. UTC | #1
On Mon, 27 Sept 2021 at 00:42, Dmitry Osipenko <digetx@gmail.com> wrote:
>
> Only couple drivers need to get the -ENODEV error code and majority of
> drivers need to explicitly initialize the performance state. Add new
> common helper which sets up OPP table for these drivers.
>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  include/soc/tegra/common.h | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>
> diff --git a/include/soc/tegra/common.h b/include/soc/tegra/common.h
> index af41ad80ec21..5b4a042f60fb 100644
> --- a/include/soc/tegra/common.h
> +++ b/include/soc/tegra/common.h
> @@ -39,4 +39,28 @@ devm_tegra_core_dev_init_opp_table(struct device *dev,
>  }
>  #endif
>
> +/*
> + * This function should be invoked with the enabled runtime PM of the device
> + * in order to initialize performance state properly. Most of Tegra devices
> + * are assumed to be suspended at a probe time and GENPD require RPM to be
> + * enabled to set up the rpm-resume state, otherwise device is active and
> + * performance state is applied immediately. Note that it will initialize
> + * OPP bandwidth if it's wired in a device-tree for this device, which is
> + * undesirable for a suspended device.
> + */
> +static inline int
> +devm_tegra_core_dev_init_opp_table_common(struct device *dev)
> +{
> +       struct tegra_core_opp_params opp_params = {};
> +       int err;
> +
> +       opp_params.init_state = true;
> +
> +       err = devm_tegra_core_dev_init_opp_table(dev, &opp_params);
> +       if (err != -ENODEV)
> +               return err;
> +
> +       return 0;
> +}

Just want to share a few thoughts around these functions.

So, I assume it's fine to call
devm_tegra_core_dev_init_opp_table_common() or
devm_tegra_core_dev_init_opp_table() from consumer drivers during
->probe(), as long as those drivers are tegra specific, which I assume
all are in the series!?

My point is, a cross SoC consumer driver that needs to initiate OPP
tables can get rather messy, if it would need to make one specific
function call per SoC.

That said, I hope we can tackle this as a separate/future problem, so
the series can get merged as is.

> +
>  #endif /* __SOC_TEGRA_COMMON_H__ */
> --
> 2.32.0
>

Kind regards
Uffe
Dmitry Osipenko Oct. 1, 2021, 7:15 p.m. UTC | #2
01.10.2021 15:50, Ulf Hansson пишет:
> On Mon, 27 Sept 2021 at 00:42, Dmitry Osipenko <digetx@gmail.com> wrote:
>>
>> Only couple drivers need to get the -ENODEV error code and majority of
>> drivers need to explicitly initialize the performance state. Add new
>> common helper which sets up OPP table for these drivers.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>> ---
>>  include/soc/tegra/common.h | 24 ++++++++++++++++++++++++
>>  1 file changed, 24 insertions(+)
>>
>> diff --git a/include/soc/tegra/common.h b/include/soc/tegra/common.h
>> index af41ad80ec21..5b4a042f60fb 100644
>> --- a/include/soc/tegra/common.h
>> +++ b/include/soc/tegra/common.h
>> @@ -39,4 +39,28 @@ devm_tegra_core_dev_init_opp_table(struct device *dev,
>>  }
>>  #endif
>>
>> +/*
>> + * This function should be invoked with the enabled runtime PM of the device
>> + * in order to initialize performance state properly. Most of Tegra devices
>> + * are assumed to be suspended at a probe time and GENPD require RPM to be
>> + * enabled to set up the rpm-resume state, otherwise device is active and
>> + * performance state is applied immediately. Note that it will initialize
>> + * OPP bandwidth if it's wired in a device-tree for this device, which is
>> + * undesirable for a suspended device.
>> + */
>> +static inline int
>> +devm_tegra_core_dev_init_opp_table_common(struct device *dev)
>> +{
>> +       struct tegra_core_opp_params opp_params = {};
>> +       int err;
>> +
>> +       opp_params.init_state = true;
>> +
>> +       err = devm_tegra_core_dev_init_opp_table(dev, &opp_params);
>> +       if (err != -ENODEV)
>> +               return err;
>> +
>> +       return 0;
>> +}
> 
> Just want to share a few thoughts around these functions.
> 
> So, I assume it's fine to call
> devm_tegra_core_dev_init_opp_table_common() or
> devm_tegra_core_dev_init_opp_table() from consumer drivers during
> ->probe(), as long as those drivers are tegra specific, which I assume
> all are in the series!?

That is correct, all drivers are tegra-specific in this series. External
devices are attached to the internal SoC devices and this series is
about the SoC power management.

> My point is, a cross SoC consumer driver that needs to initiate OPP
> tables can get rather messy, if it would need to make one specific
> function call per SoC.
> 
> That said, I hope we can tackle this as a separate/future problem, so
> the series can get merged as is.

Yes, as we already have seen, it's not an easy problem to make PD core
to handle it in a generic way. If there will be a similar demand from
other SoCs, then we may try to solve that problem again.
diff mbox series

Patch

diff --git a/include/soc/tegra/common.h b/include/soc/tegra/common.h
index af41ad80ec21..5b4a042f60fb 100644
--- a/include/soc/tegra/common.h
+++ b/include/soc/tegra/common.h
@@ -39,4 +39,28 @@  devm_tegra_core_dev_init_opp_table(struct device *dev,
 }
 #endif
 
+/*
+ * This function should be invoked with the enabled runtime PM of the device
+ * in order to initialize performance state properly. Most of Tegra devices
+ * are assumed to be suspended at a probe time and GENPD require RPM to be
+ * enabled to set up the rpm-resume state, otherwise device is active and
+ * performance state is applied immediately. Note that it will initialize
+ * OPP bandwidth if it's wired in a device-tree for this device, which is
+ * undesirable for a suspended device.
+ */
+static inline int
+devm_tegra_core_dev_init_opp_table_common(struct device *dev)
+{
+	struct tegra_core_opp_params opp_params = {};
+	int err;
+
+	opp_params.init_state = true;
+
+	err = devm_tegra_core_dev_init_opp_table(dev, &opp_params);
+	if (err != -ENODEV)
+		return err;
+
+	return 0;
+}
+
 #endif /* __SOC_TEGRA_COMMON_H__ */