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SubjectRe: [PATCH V4 4/8] driver/core: cpu: initialize opp table
Date
On Tuesday, May 27, 2014 05:20:53 PM Viresh Kumar wrote:
> Drivers expecting CPU's OPPs from device tree initialize OPP table themselves by
> calling of_init_opp_table() and there is nothing driver specific in that. They
> all do it in the same redundant way.
>
> It would be better if we can get rid of redundancy by initializing CPU OPPs from
> CPU core code for all CPUs (that have a "operating-points" property defined in
> their node).
>
> This patch calls of_init_opp_table() right after CPU device is registered in
> register_cpu(). of_init_opp_table() also has a dummy implementation which simply
> returns -ENOSYS when CONFIG_OPP or CONFIG_OF isn't supported by some platform.
>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Amit Daniel Kachhap <amit.daniel@samsung.com>
> Cc: Kukjin Kim <kgene.kim@samsung.com>
> Cc: Shawn Guo <shawn.guo@linaro.org>
> Cc: Sudeep Holla <sudeep.holla@arm.com>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
> drivers/base/cpu.c | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
> index 006b1bc..790183f 100644
> --- a/drivers/base/cpu.c
> +++ b/drivers/base/cpu.c
> @@ -16,6 +16,7 @@
> #include <linux/acpi.h>
> #include <linux/of.h>
> #include <linux/cpufeature.h>
> +#include <linux/pm_opp.h>
>
> #include "base.h"
>
> @@ -349,10 +350,12 @@ int register_cpu(struct cpu *cpu, int num)
> if (cpu->hotpluggable)
> cpu->dev.groups = hotplugable_cpu_attr_groups;
> error = device_register(&cpu->dev);
> - if (!error)
> - per_cpu(cpu_sys_devices, num) = &cpu->dev;
> - if (!error)
> - register_cpu_under_node(num, cpu_to_node(num));
> + if (error)
> + return error;
> +
> + per_cpu(cpu_sys_devices, num) = &cpu->dev;
> + register_cpu_under_node(num, cpu_to_node(num));
> + of_init_opp_table(&cpu->dev);

Having thought a bit more about that I don't really like this.

In the ACPI land we have a processor driver that binds to CPU devices and
carries out similar initialization. I kind of prefer that to littering
core code with platform-specific stuff.

Rafael



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