Re: [PATCH v2 09/15] PM / devfreq: Switch to dev_pm_opp_find_freq_{ceil/floor}_indexed() APIs

From: Chanwoo Choi
Date: Sun Jul 23 2023 - 16:07:10 EST


Hi,

On 23. 7. 20. 14:40, Manivannan Sadhasivam wrote:
> Some devfreq consumers like UFS driver need to work with multiple clocks
> through the OPP framework. For this reason, OPP framework exposes the
> _indexed() APIs for finding the floor/ceil of the supplied frequency of
> the indexed clock. So let's use them in the devfreq driver.
>
> Currently, the clock index of 0 is used which works fine for multiple as
> well as single clock.
>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> ---
> drivers/devfreq/devfreq.c | 14 +++++++-------
> 1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index e36cbb920ec8..7686993d639f 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -88,7 +88,7 @@ static unsigned long find_available_min_freq(struct devfreq *devfreq)
> struct dev_pm_opp *opp;
> unsigned long min_freq = 0;
>
> - opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &min_freq);
> + opp = dev_pm_opp_find_freq_ceil_indexed(devfreq->dev.parent, &min_freq, 0);

This patch changed the used function from dev_pm_opp_find_freq_ceil
to dev_pm_opp_find_freq_ceil_indexed even if there are no supporting of the multiple clocks
and then dev_pm_opp_find_freq_ceil is not removed from OPP.

I think that it is better to use dev_pm_opp_find_freq_ceil_indexed
when need to support multiple clocks with real case.

> if (IS_ERR(opp))
> min_freq = 0;
> else
> @@ -102,7 +102,7 @@ static unsigned long find_available_max_freq(struct devfreq *devfreq)
> struct dev_pm_opp *opp;
> unsigned long max_freq = ULONG_MAX;
>
> - opp = dev_pm_opp_find_freq_floor(devfreq->dev.parent, &max_freq);
> + opp = dev_pm_opp_find_freq_floor_indexed(devfreq->dev.parent, &max_freq, 0);
> if (IS_ERR(opp))
> max_freq = 0;
> else
> @@ -196,7 +196,7 @@ static int set_freq_table(struct devfreq *devfreq)
> return -ENOMEM;
>
> for (i = 0, freq = 0; i < devfreq->max_state; i++, freq++) {
> - opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &freq);
> + opp = dev_pm_opp_find_freq_ceil_indexed(devfreq->dev.parent, &freq, 0);
> if (IS_ERR(opp)) {
> devm_kfree(devfreq->dev.parent, devfreq->freq_table);
> return PTR_ERR(opp);
> @@ -2034,18 +2034,18 @@ struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
>
> if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) {
> /* The freq is an upper bound. opp should be lower */
> - opp = dev_pm_opp_find_freq_floor(dev, freq);
> + opp = dev_pm_opp_find_freq_floor_indexed(dev, freq, 0);
>
> /* If not available, use the closest opp */
> if (opp == ERR_PTR(-ERANGE))
> - opp = dev_pm_opp_find_freq_ceil(dev, freq);
> + opp = dev_pm_opp_find_freq_ceil_indexed(dev, freq, 0);
> } else {
> /* The freq is an lower bound. opp should be higher */
> - opp = dev_pm_opp_find_freq_ceil(dev, freq);
> + opp = dev_pm_opp_find_freq_ceil_indexed(dev, freq, 0);
>
> /* If not available, use the closest opp */
> if (opp == ERR_PTR(-ERANGE))
> - opp = dev_pm_opp_find_freq_floor(dev, freq);
> + opp = dev_pm_opp_find_freq_floor_indexed(dev, freq, 0);
> }
>
> return opp;

--
Best Regards,
Samsung Electronics
Chanwoo Choi