Re: [PATCH v4 12/19] cpufreq: cpufreq-cpu0: remove device treeparsing for cpu nodes

From: Guennadi Liakhovetski
Date: Sun Sep 08 2013 - 11:29:16 EST


Hi

On Tue, 20 Aug 2013, Sudeep KarkadaNagesha wrote:

> From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@xxxxxxx>
>
> Now that the cpu device registration initialises the of_node(if available)
> appropriately for all the cpus, parsing here is redundant.
>
> This patch removes all DT parsing and uses cpu->of_node instead.
>
> Acked-by: Shawn Guo <shawn.guo@xxxxxxxxxx>
> Acked-by: Rob Herring <rob.herring@xxxxxxxxxxx>
> Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
> Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@xxxxxxx>
> ---
> drivers/cpufreq/cpufreq-cpu0.c | 23 ++++-------------------
> 1 file changed, 4 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.=
> c
> index ad1fde2..5b05c26 100644
> --- a/drivers/cpufreq/cpufreq-cpu0.c
> +++ b/drivers/cpufreq/cpufreq-cpu0.c
> @@ -174,29 +174,17 @@ static struct cpufreq_driver cpu0_cpufreq_driver =3D =
> {
> =20
> static int cpu0_cpufreq_probe(struct platform_device *pdev)
> {
> -=09struct device_node *np, *parent;
> +=09struct device_node *np;
> =09int ret;
> =20
> -=09parent =3D of_find_node_by_path("/cpus");
> -=09if (!parent) {
> -=09=09pr_err("failed to find OF /cpus\n");
> -=09=09return -ENOENT;
> -=09}
> -
> -=09for_each_child_of_node(parent, np) {
> -=09=09if (of_get_property(np, "operating-points", NULL))
> -=09=09=09break;
> -=09}
> +=09cpu_dev =3D &pdev->dev;
> =20
> +=09np =3D of_node_get(cpu_dev->of_node);

Has this actually been tested? This seems to break cpufreq-cpu0. The
reason is, that this probe function is called not for the DT CPU node, but
for a special virtual cpufreq-cpu0 platform device, typically created by
platforms, using

platform_device_register_simple("cpufreq-cpu0", -1, NULL, 0);

which then of course doesn't have on .of_node associated with it.

Thanks
Guennadi

> =09if (!np) {
> =09=09pr_err("failed to find cpu0 node\n");
> -=09=09ret =3D -ENOENT;
> -=09=09goto out_put_parent;
> +=09=09return -ENOENT;
> =09}
> =20
> -=09cpu_dev =3D &pdev->dev;
> -=09cpu_dev->of_node =3D np;
> -
> =09cpu_reg =3D devm_regulator_get(cpu_dev, "cpu0");
> =09if (IS_ERR(cpu_reg)) {
> =09=09/*
> @@ -269,15 +257,12 @@ static int cpu0_cpufreq_probe(struct platform_device =
> *pdev)
> =09}
> =20
> =09of_node_put(np);
> -=09of_node_put(parent);
> =09return 0;
> =20
> out_free_table:
> =09opp_free_cpufreq_table(cpu_dev, &freq_table);
> out_put_node:
> =09of_node_put(np);
> -out_put_parent:
> -=09of_node_put(parent);
> =09return ret;
> }
> =20
> --=20
> 1.8.1.2
>
>
> --
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---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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