Re: [PATCH v2 4/4] PM / devfreq: Add required OPPs support to passive governor
From: Chanwoo Choi
Date: Tue Jun 25 2019 - 21:56:49 EST
Hi Saravana,
On 19. 6. 26. ìì 6:33, Saravana Kannan wrote:
> Look at the required OPPs of the "parent" device to determine the OPP that
> is required from the slave device managed by the passive governor. This
> allows having mappings between a parent device and a slave device even when
> they don't have the same number of OPPs.
>
> Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx>
> ---
> drivers/devfreq/governor_passive.c | 20 +++++++++++++++-----
> 1 file changed, 15 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
> index 3bc29acbd54e..f6de03de7a64 100644
> --- a/drivers/devfreq/governor_passive.c
> +++ b/drivers/devfreq/governor_passive.c
> @@ -22,7 +22,7 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
> = (struct devfreq_passive_data *)devfreq->data;
> struct devfreq *parent_devfreq = (struct devfreq *)p_data->parent;
> unsigned long child_freq = ULONG_MAX;
> - struct dev_pm_opp *opp;
> + struct dev_pm_opp *opp = NULL, *p_opp = NULL;
> int i, count, ret = 0;
>
> /*
> @@ -59,13 +59,20 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
> * list of parent device. Because in this case, *freq is temporary
> * value which is decided by ondemand governor.
> */
> - opp = devfreq_recommended_opp(parent_devfreq->dev.parent, freq, 0);
> - if (IS_ERR(opp)) {
> - ret = PTR_ERR(opp);
> + p_opp = devfreq_recommended_opp(parent_devfreq->dev.parent, freq, 0);
> + if (IS_ERR(p_opp)) {
> + ret = PTR_ERR(p_opp);
> goto out;
> }
>
> - dev_pm_opp_put(opp);
> + if (devfreq->opp_table && parent_devfreq->opp_table)
> + opp = dev_pm_opp_xlate_opp(parent_devfreq->opp_table,
> + devfreq->opp_table, p_opp);
> + if (opp) {
> + *freq = dev_pm_opp_get_freq(opp);
> + dev_pm_opp_put(opp);
> + goto out;
> + }
>
> /*
> * Get the OPP table's index of decided freqeuncy by governor
> @@ -92,6 +99,9 @@ static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
> *freq = child_freq;
>
> out:
> + if (!IS_ERR_OR_NULL(opp))
> + dev_pm_opp_put(p_opp);
> +
> return ret;
> }
>
>
I agree this approach. It is necessary.
Acked-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
--
Best Regards,
Chanwoo Choi
Samsung Electronics