Re: [PATCH] opp: of: Allow lazy-linking of required-opps to non genpd

From: Viresh Kumar
Date: Wed Jun 16 2021 - 03:55:56 EST


On 16-06-21, 13:33, Hsin-Yi Wang wrote:
> Don't limit required_opp_table to genpd only. One possible use case is
> cpufreq based devfreq governor, which can use required-opps property to
> derive devfreq from cpufreq.
>
> Suggested-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
> Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
> ---
> This is tested with the non genpd case mt8183-cci with passive
> governor[1].
> [1] https://patchwork.kernel.org/project/linux-mediatek/patch/1616499241-4906-2-git-send-email-andrew-sh.cheng@xxxxxxxxxxxx/
> ---
> drivers/opp/of.c | 20 +-------------------
> 1 file changed, 1 insertion(+), 19 deletions(-)
>
> diff --git a/drivers/opp/of.c b/drivers/opp/of.c
> index aa75a1caf08a3..9573facce53a5 100644
> --- a/drivers/opp/of.c
> +++ b/drivers/opp/of.c
> @@ -201,17 +201,6 @@ static void _opp_table_alloc_required_tables(struct opp_table *opp_table,
> lazy = true;
> continue;
> }
> -
> - /*
> - * We only support genpd's OPPs in the "required-opps" for now,
> - * as we don't know how much about other cases. Error out if the
> - * required OPP doesn't belong to a genpd.
> - */
> - if (!required_opp_tables[i]->is_genpd) {
> - dev_err(dev, "required-opp doesn't belong to genpd: %pOF\n",
> - required_np);
> - goto free_required_tables;
> - }
> }
>
> /* Let's do the linking later on */
> @@ -379,13 +368,6 @@ static void lazy_link_required_opp_table(struct opp_table *new_table)
> struct dev_pm_opp *opp;
> int i, ret;
>
> - /*
> - * We only support genpd's OPPs in the "required-opps" for now,
> - * as we don't know much about other cases.
> - */
> - if (!new_table->is_genpd)
> - return;
> -
> mutex_lock(&opp_table_lock);
>
> list_for_each_entry_safe(opp_table, temp, &lazy_opp_tables, lazy) {
> @@ -873,7 +855,7 @@ static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
> return ERR_PTR(-ENOMEM);
>
> ret = _read_opp_key(new_opp, opp_table, np, &rate_not_available);
> - if (ret < 0 && !opp_table->is_genpd) {
> + if (ret < 0) {
> dev_err(dev, "%s: opp key field not found\n", __func__);
> goto free_opp;
> }

Plus this and few changes to commit log.

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index e366218d6736..b335c077f215 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -893,6 +893,16 @@ static int _set_required_opps(struct device *dev,
if (!required_opp_tables)
return 0;

+ /*
+ * We only support genpd's OPPs in the "required-opps" for now, as we
+ * don't know much about other use cases. Error out if the required OPP
+ * doesn't belong to a genpd.
+ */
+ if (unlikely(!required_opp_tables[0]->is_genpd)) {
+ dev_err(dev, "required-opps don't belong to a genpd\n");
+ return -ENOENT;
+ }
+
/* required-opps not fully initialized yet */
if (lazy_linking_pending(opp_table))
return -EBUSY;

Applied. Thanks.

--
viresh