Re: [PATCH v2 08/15] iio: adc: rzg2l_adc: Enable runtime PM autosuspend support

Lad, Prabhakar
2024-12-08T21:00:42Z

On Fri, Dec 6, 2024 at 11:15 AM Claudiu <claudiu.beznea@tuxon.dev> wrote:
>
> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
>
> Enable runtime PM autosuspend support for the rzg2l_adc driver. With this
> change, consecutive conversion requests will no longer cause the device to
> be runtime-enabled/disabled after each request. Instead, the device will
> transition based on the delay configured by the user.
>
> This approach reduces the frequency of hardware register access during
> runtime PM suspend/resume cycles, thereby saving CPU cycles.
>
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> ---
>
> Changes in v2:
> - used a non-zero default autosusped delay
> - adjusted the patch description to reflect that the default autosuspend
> delay has been changed
>
> drivers/iio/adc/rzg2l_adc.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Cheers,
Prabhakar

> diff --git a/drivers/iio/adc/rzg2l_adc.c b/drivers/iio/adc/rzg2l_adc.c
> index 953511191eac..c3f9f95cdbba 100644
> --- a/drivers/iio/adc/rzg2l_adc.c
> +++ b/drivers/iio/adc/rzg2l_adc.c
> @@ -208,7 +208,8 @@ static int rzg2l_adc_conversion(struct iio_dev *indio_dev, struct rzg2l_adc *adc
> rzg2l_adc_start_stop(adc, false);
>
> rpm_put:
> - pm_runtime_put_sync(dev);
> + pm_runtime_mark_last_busy(dev);
> + pm_runtime_put_autosuspend(dev);
> return ret;
> }
>
> @@ -372,7 +373,8 @@ static int rzg2l_adc_hw_init(struct device *dev, struct rzg2l_adc *adc)
> rzg2l_adc_writel(adc, RZG2L_ADM(3), reg);
>
> exit_hw_init:
> - pm_runtime_put_sync(dev);
> + pm_runtime_mark_last_busy(dev);
> + pm_runtime_put_autosuspend(dev);
> return ret;
> }
>
> @@ -410,6 +412,8 @@ static int rzg2l_adc_probe(struct platform_device *pdev)
> "failed to get/deassert presetn\n");
> }
>
> + pm_runtime_set_autosuspend_delay(dev, 300);
> + pm_runtime_use_autosuspend(dev);
> ret = devm_pm_runtime_enable(dev);
> if (ret)
> return ret;
> --
> 2.39.2
>
>