Re: [PATCH 6/9] OPP: Extend support for the opp-level beyond required-opps

From: Ulf Hansson
Date: Mon Sep 25 2023 - 09:34:31 EST


On Mon, 25 Sept 2023 at 15:18, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
>
> At this point the level (performance state) for an OPP is currently limited
> to be requested for a device that is attached to a PM domain. Moreover,
> the device needs to have the so called required-opps assigned to it, which
> are based upon OPP tables being described in DT.
>
> To extend the support beyond required-opps and DT, let's enable the level
> to be set for all OPPs. More precisely, if the requested OPP has a valid
> level let's try to request it through the device's optional PM domain, via
> calling dev_pm_domain_set_performance_state().
>
> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> ---
> drivers/opp/core.c | 29 +++++++++++++++++++++++++++++
> 1 file changed, 29 insertions(+)
>
> diff --git a/drivers/opp/core.c b/drivers/opp/core.c
> index 60dca60ac4af..afb73978cdcb 100644
> --- a/drivers/opp/core.c
> +++ b/drivers/opp/core.c
> @@ -1107,6 +1107,22 @@ void _update_set_required_opps(struct opp_table *opp_table)
> opp_table->set_required_opps = _opp_set_required_opps_generic;
> }
>
> +static int _set_opp_level(struct device *dev, struct opp_table *opp_table,
> + struct dev_pm_opp *opp)
> +{
> + int ret = 0;
> +
> + /* Request a new performance state through the device's PM domain. */
> + if (opp && opp->level) {
> + ret = dev_pm_domain_set_performance_state(dev, opp->level);
> + if (ret)
> + dev_err(dev, "Failed to set performance state %u (%d)\n",
> + opp->level, ret);
> + }

Okay, so reviewing my own code found a problem here. We need an "else"
here, that should request the performance state to be set to 0.

I am not sending a new version at this point, but awaiting more feedback first.

> +
> + return ret;
> +}
> +
> static void _find_current_opp(struct device *dev, struct opp_table *opp_table)
> {
> struct dev_pm_opp *opp = ERR_PTR(-ENODEV);
> @@ -1154,8 +1170,13 @@ static int _disable_opp_table(struct device *dev, struct opp_table *opp_table)
> if (opp_table->regulators)
> regulator_disable(opp_table->regulators[0]);
>
> + ret = _set_opp_level(dev, opp_table, NULL);
> + if (ret)
> + goto out;
> +
> ret = _set_required_opps(dev, opp_table, NULL, false);
>
> +out:
> opp_table->enabled = false;
> return ret;
> }
> @@ -1198,6 +1219,10 @@ static int _set_opp(struct device *dev, struct opp_table *opp_table,
> return ret;
> }
>
> + ret = _set_opp_level(dev, opp_table, opp);
> + if (ret)
> + return ret;
> +
> ret = _set_opp_bw(opp_table, opp, dev);
> if (ret) {
> dev_err(dev, "Failed to set bw: %d\n", ret);
> @@ -1241,6 +1266,10 @@ static int _set_opp(struct device *dev, struct opp_table *opp_table,
> return ret;
> }
>
> + ret = _set_opp_level(dev, opp_table, opp);
> + if (ret)
> + return ret;
> +
> ret = _set_required_opps(dev, opp_table, opp, false);
> if (ret) {
> dev_err(dev, "Failed to set required opps: %d\n", ret);
> --
> 2.34.1
>

Kind regards
Uffe