Re: [PATCH v14 20/39] pwm: tegra: Add runtime PM and OPP support

Dmitry Osipenko
2021-10-29T15:20:55Z

26.10.2021 01:40, Dmitry Osipenko пишет:
> + ret = devm_pm_runtime_enable(&pdev->dev);
> + if (ret)
> + return ret;
> +
> + ret = devm_tegra_core_dev_init_opp_table_common(&pdev->dev);
> + if (ret)
> + return ret;
> +
> + ret = pm_runtime_resume_and_get(&pdev->dev);
> + if (ret)
> + return ret;
> +
> /* Set maximum frequency of the IP */
> - ret = clk_set_rate(pwm->clk, pwm->soc->max_frequency);
> + ret = dev_pm_opp_set_rate(pwm->dev, pwm->soc->max_frequency);
> if (ret < 0) {
> dev_err(&pdev->dev, "Failed to set max frequency: %d\n", ret);
> - return ret;
> + goto put_pm;
> }
>
> /*
> @@ -278,7 +294,7 @@ static int tegra_pwm_probe(struct platform_device *pdev)
> if (IS_ERR(pwm->rst)) {
> ret = PTR_ERR(pwm->rst);
> dev_err(&pdev->dev, "Reset control is not found: %d\n", ret);
> - return ret;
> + goto put_pm;
> }
>
> reset_control_deassert(pwm->rst);
> @@ -291,10 +307,15 @@ static int tegra_pwm_probe(struct platform_device *pdev)
> if (ret < 0) {
> dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
> reset_control_assert(pwm->rst);
> - return ret;
> + goto put_pm;
> }
>
> + pm_runtime_put(&pdev->dev);
> +
> return 0;
> +put_pm:
> + pm_runtime_put_sync_suspend(&pdev->dev);
> + return ret;
> }
>
> static int tegra_pwm_remove(struct platform_device *pdev)
> @@ -305,20 +326,44 @@ static int tegra_pwm_remove(struct platform_device *pdev)
>
> reset_control_assert(pc->rst);
>
> + pm_runtime_force_suspend(&pdev->dev);

I just noticed that RPM core doesn't reset RPM-enable count of a device
on driver's unbind (pm_runtime_reinit). It was a bad idea to use
devm_pm_runtime_enable() + pm_runtime_force_suspend() here, since RPM is
disabled twice on driver's removal, and thus, RPM will never be enabled
again.

I'll fix it for PWM and other drivers in this series, in v15.