diff mbox

[4/5] Thermal: make sure cpufreq cooling register after cpufreq driver

Message ID 1350387889-15324-5-git-send-email-hongbo.zhang@linaro.com (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Hongbo Zhang Oct. 16, 2012, 11:44 a.m. UTC
From: "hongbo.zhang" <hongbo.zhang@linaro.com>

The cpufreq works as a cooling device, so the cooling layer should
check and wait until the cpufreq driver is initialized.

Signed-off-by: hongbo.zhang <hongbo.zhang@linaro.com>
---
 drivers/thermal/cpu_cooling.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

Comments

Viresh Kumar Oct. 17, 2012, 2:36 p.m. UTC | #1
On 16 October 2012 17:14, hongbo.zhang <hongbo.zhang@linaro.org> wrote:
> From: "hongbo.zhang" <hongbo.zhang@linaro.com>
>
> The cpufreq works as a cooling device, so the cooling layer should
> check and wait until the cpufreq driver is initialized.

Idea is good.

> Signed-off-by: hongbo.zhang <hongbo.zhang@linaro.com>
> ---
>  drivers/thermal/cpu_cooling.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
> index d196230..01aba58 100644
> --- a/drivers/thermal/cpu_cooling.c
> +++ b/drivers/thermal/cpu_cooling.c
> @@ -29,6 +29,7 @@
>  #include <linux/slab.h>
>  #include <linux/cpu.h>
>  #include <linux/cpu_cooling.h>
> +#include <linux/delay.h>

Would be better if we add them alphabetically. That makes there maintenance
easier. I know the list is already mismanaged. :)

If you can add another patch here to fix that, would be good.

>  /**
>   * struct cpufreq_cooling_device
> @@ -352,9 +353,18 @@ struct thermal_cooling_device *cpufreq_cooling_register(
>         struct cpufreq_cooling_device *cpufreq_dev = NULL;
>         unsigned int cpufreq_dev_count = 0, min = 0, max = 0;
>         char dev_name[THERMAL_NAME_LENGTH];
> -       int ret = 0, i;
> +       int ret = 0, to = 1000, i;
>         struct cpufreq_policy policy;
>
> +       /* make sure cpufreq driver is initialized */
> +       while (!cpufreq_frequency_get_table(0) && --to)
> +               mdelay(10);
> +
> +       if (!to) {
> +               pr_err("No cpufreq driver act as cooling device.\n");
> +               return ERR_PTR(-ENOSYS);
> +       }

I understand that you want cpufreq to be there before this thing, but
i didn't like the idea here. There should be something else like
returning -EPROBE_DEFER, so that driver can be pinged again.

--
viresh
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diff mbox

Patch

diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
index d196230..01aba58 100644
--- a/drivers/thermal/cpu_cooling.c
+++ b/drivers/thermal/cpu_cooling.c
@@ -29,6 +29,7 @@ 
 #include <linux/slab.h>
 #include <linux/cpu.h>
 #include <linux/cpu_cooling.h>
+#include <linux/delay.h>
 
 /**
  * struct cpufreq_cooling_device
@@ -352,9 +353,18 @@  struct thermal_cooling_device *cpufreq_cooling_register(
 	struct cpufreq_cooling_device *cpufreq_dev = NULL;
 	unsigned int cpufreq_dev_count = 0, min = 0, max = 0;
 	char dev_name[THERMAL_NAME_LENGTH];
-	int ret = 0, i;
+	int ret = 0, to = 1000, i;
 	struct cpufreq_policy policy;
 
+	/* make sure cpufreq driver is initialized */
+	while (!cpufreq_frequency_get_table(0) && --to)
+		mdelay(10);
+
+	if (!to) {
+		pr_err("No cpufreq driver act as cooling device.\n");
+		return ERR_PTR(-ENOSYS);
+	}
+
 	list_for_each_entry(cpufreq_dev, &cooling_cpufreq_list, node)
 		cpufreq_dev_count++;