Messages in this thread | | | Date | Thu, 20 Jun 2013 08:41:08 +0200 | From | Lukasz Majewski <> | Subject | Re: [PATCH v3 1/3] cpufreq: Add boost frequency support in core |
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On Thu, 20 Jun 2013 10:41:41 +0530, Viresh Kumar wrote: > On 19 June 2013 12:46, Lukasz Majewski <l.majewski@samsung.com> wrote: > > I would like to clarify the above issue. > > > > When I've discussed with Viresh previous version of this patch, we > > have agreed, that "boost" sysfs attribute [*]: > > /sys/devices/system/cpu/cpufreq/boost > > > > would be only visible when boost_supported flag is set at cpufreq > > driver. > > Yes. > > > When acpi-cpufreq driver doesn't support boost, the attribute [*] > > won't be exported at all. This contradicts the documentation and > > legacy acpi-cpufreq behaviour. > > No they aren't contradictory. What the documentation meant was: > acpi-cpufreq driver is used by lots of different x86 processors. Now > all processors might not support boost inside x86 also. And for them > we will keep 'boost' file readonly. This is done by following > statement
Thanks for explanation.
> > if (boot_cpu_has(X86_FEATURE_CPB) || > boot_cpu_has(X86_FEATURE_IDA)) { boost_supported = true; > .... > } else > global_boost.attr.mode = 0444;
Grrr.... So simple and obvious solution [1].
> > Documentation file doesn't talk about any other cpufreq driver, for > them there is no concept like boost. > > You need to preserve this functionality.
Yes the idea [1], solves problem with legacy API.
> > > Since I'm affraid to break API (with all its consequences :-) ), I > > would like to be sure that this is OK, and thereof I'm allowed to > > rewrite documentation accordingly. > > > > I simply need explicit permission from both maintainers :-). > > For me its okay to rewrite documentation.
I will extent documentation about the SW managed boost.
-- Best regards,
Lukasz Majewski
Samsung R&D Institute Poland (SRPOL) | Linux Platform Group
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