Re: [PATCH V3 2/5] PM / QOS: Pass request type to dev_pm_qos_read_value()

From: Rafael J. Wysocki
Date: Mon Jun 17 2019 - 19:19:17 EST

On Monday, June 10, 2019 12:51:33 PM CEST Viresh Kumar wrote:
> In order to use dev_pm_qos_read_value(), and other internal routines to
> it, to read values for different QoS requests, pass request type as a
> parameter to these routines.
> For now, it only supports resume-latency request type.

I don't quite like the structure by which the type arg is passed through the
entire call chain until the switch in dep_pm_qos_raw_read_value().

There is only one direct user of dev_pm_qos_raw_read_value() AFAICS which
is cpuidle. It shouldn't need to suffer the general case overhead, so I would
rename that function to dev_pm_qos_raw_resume_latency() and update cpuidle

Moreover, the callers of __dev_pm_qos_read_value() are interested in the
resume latency value too, so it might make sense to rename this as
__dev_pm_qos_resume_latency(), update its callers and put the switch
into dev_pm_qos_read_value().

Plus the changelog should explain the broader rationale of this change like
for the first patch IMO.