On 06/09/13 14:44, Guennadi Liakhovetski wrote:

Hi

On Tue, 20 Aug 2013, Sudeep KarkadaNagesha wrote:

quoted

From: Sudeep KarkadaNagesha <redacted>

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 <redacted>
Acked-by: Rob Herring <redacted>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep KarkadaNagesha <redacted>
---
 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.

Hi Guennadi,

Based on my understanding of the original code:
        cpu_dev = &pdev->dev;
	...
	ret = of_init_opp_table(cpu_dev);

of_init_opp_table needs cpu_dev to be get_cpu_device(0). My
understanding was that platform using cpufreq-cpu0 sets &pdev->dev to
get_cpu_device(0). But looks like that's not the case.

Hi Shawn,

Can you please clarify ? The fix would be as below but I would like to
know if setting cpu_dev to get_cpu_device(0) instead of &pdev->dev has
any impact on other parts of code using cpu_dev ?

diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
index cbfffa9..871c336 100644
--- a/drivers/cpufreq/cpufreq-cpu0.c
+++ b/drivers/cpufreq/cpufreq-cpu0.c

@@ -177,7 +177,7 @@ static int cpu0_cpufreq_probe(struct platform_device

*pdev)
        struct device_node *np;
        int ret;

-       cpu_dev = &pdev->dev;
+       cpu_dev = get_cpu_device(0);

        np = of_node_get(cpu_dev->of_node);
        if (!np) {


Regards,
Sudeep