On Wed, Aug 24, 2011 at 2:29 AM, Turquette, Mike <mturquette@xxxxxx> wrote:
> On Tue, Aug 23, 2011 at 12:54 AM, MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx> wrote:
>
> I think that user_set_freq == 0 is a valid request from a user. A
> user might not know what the valid frequencies are for a device, but
> knows that he/she wants the lowest one. Writing 0 to the sysfs value
> should give the floor of the available frequencies.
>
Users can know what is the minimum valid frequency with
devfreq_min_freq. However, writing 0 to the sysfs is a comfortable
method and I'll allow that input in the next revision along with the
patch of allowing governors to have their own sysfs entries with
example of userspace.
>> + else
>> + *freq = df->user_set_freq;
>> +
>> + return 0;
>> +}
>> +
>> +struct devfreq_governor devfreq_userspace = {
>> + .name = "userspace",
>> + .get_target_freq = devfreq_userspace_func,
>> +};
>
> The set_user_frequency attribute should be moved out of devfreq.c
> (patch 4) and live here. There is no purpose to that entry except for
> the userspace governor and it should not exist in sysfs unless this
> governor is in use. To be clear, there should still be a read-only
> show_frequency or something in devfreq.c.
>
> This again touches on my long-standing complaints with this series'
> design. set_user_frequency is an attribute that belongs to the
> governor, not to the core. Such misplacement of attribute/entity
> ownership is common in this series, but I won't go down that rabbit
> hole again. In the mean time at least this one instance of the
> problem for the userspace gov should be fixed up.
>
> Regards,
> Mike
>
I'll include a patch that shows an example of having a governor
specific sysfs entry at the next revision. It is enabled by
introducing a function to governors "struct devfreq
*get_devfreq(struct device *dev);" at /device/devfreq/governor.h
(local to governors) and adding .init and .exit callbacks at struct
devfreq_governor.
Cheers!
MyungJoo
--
MyungJoo Ham (함명주), Ph.D.
Mobile Software Platform Lab,
Digital Media and Communications (DMC) Business
Samsung Electronics
cell: 82-10-6714-2858
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