On Wed, Aug 24, 2011 at 2:29 AM, Turquette, Mike [off-list ref] wrote:

On Tue, Aug 23, 2011 at 12:54 AM, MyungJoo Ham [off-list ref] 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.

quoted

+       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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