Re: [PATCH] OPP: Fix handling of multiple power domains

From: Viresh Kumar
Date: Thu Mar 07 2019 - 23:37:21 EST


On 06-03-19, 09:37, Rajendra Nayak wrote:
> We seem to rely on the number of phandles specified in the
> 'required-opps' property to identify cases where a device is
> associated with multiple power domains and hence would have
> multiple virtual devices that have to be dealt with.
>
> In cases where we do have devices with multiple power domains
> but with only one of them being scalable, this logic seems to
> fail.
>
> Instead read the number of power domains from DT to identify
> such cases.
>
> Signed-off-by: Rajendra Nayak <rnayak@xxxxxxxxxxxxxx>
> ---
> drivers/opp/of.c | 16 ++++++++++++++--
> 1 file changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/opp/of.c b/drivers/opp/of.c
> index 06f0f632ec47..443c305ae100 100644
> --- a/drivers/opp/of.c
> +++ b/drivers/opp/of.c
> @@ -172,7 +172,7 @@ static void _opp_table_alloc_required_tables(struct opp_table *opp_table,
> struct opp_table **required_opp_tables;
> struct device **genpd_virt_devs = NULL;
> struct device_node *required_np, *np;
> - int count, i;
> + int count, count_pd, i;
>
> /* Traversing the first OPP node is all we need */
> np = of_get_next_available_child(opp_np, NULL);
> @@ -185,7 +185,19 @@ static void _opp_table_alloc_required_tables(struct opp_table *opp_table,
> if (!count)
> goto put_np;
>
> - if (count > 1) {
> + /*
> + * Check the number of power-domains to know if we need to deal
> + * with virtual devices. In some cases we have devices with multiple
> + * power domains but with only one of them being scalable, hence
> + * 'count' could be 1, but we still have to deal with multiple genpds
> + * and virtual devices.
> + */
> + count_pd = of_count_phandle_with_args(dev->of_node, "power-domains",
> + "#power-domain-cells");
> + if (!count_pd)
> + goto put_np;
> +
> + if (count_pd > 1) {
> genpd_virt_devs = kcalloc(count, sizeof(*genpd_virt_devs),
> GFP_KERNEL);
> if (!genpd_virt_devs)

Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>

@Rafael, please pick this up for 5.1-rc2 directly. Thanks.

--
viresh