Messages in this thread |  | | Date | Fri, 26 Jul 2013 13:21:20 +0200 | From | Lukasz Majewski <> | Subject | Re: [PATCH v6 5/8] cpufreq:boost:Kconfig: Provide support for software managed BOOST |
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On Fri, 26 Jul 2013 15:54:56 +0530 Viresh Kumar wrote, > On 25 July 2013 22:03, Lukasz Majewski <l.majewski@samsung.com> wrote: > > For safety reasons new flag - CONFIG_CPU_FREQ_BOOST_SW has been > > added. Only after selecting "EXYNOS Frequency Overclocking - > > Software" Kconfig > > You shouldn't mention Exynos here and must do exynos stuff at the end > in a separate patch. This one must be generic.
Please see below comments.
> > > option the software managed boost is enabled. It also selects > > thermal subsystem to be compiled in. Thermal is necessary for > > disabling boost and cooling down the device when overheating > > detected. > > > > Boost _MUST_NOT_ work without thermal subsystem with properly > > defined overheating temperatures. > > > > This option doesn't affect x86's ACPI hardware managed boost support > > (i.e. Intel, AMD). In this situation boost management is embedded at > > hardware. > > > > Signed-off-by: Lukasz Majewski <l.majewski@samsung.com> > > Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com> > > > > --- > > Changes for v6: > > - CPU_FREQ_BOOST_SW [1] is now defined as "invisible" bool option. > > - Platform dependent ARM_EXYNOS_CPU_FREQ_BOOST_SW config option has > > been added. It depends on ARM_EXYNOS_CPUFREQ options and selects > > EXYNOS_THERMAL with the main boost config [1]. > > > > Changes for v5: > > - New patch > > > > drivers/cpufreq/Kconfig | 3 +++ > > drivers/cpufreq/Kconfig.arm | 16 ++++++++++++++++ > > 2 files changed, 19 insertions(+) > > > > diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig > > index 534fcb8..3f058a3 100644 > > --- a/drivers/cpufreq/Kconfig > > +++ b/drivers/cpufreq/Kconfig > > @@ -23,6 +23,9 @@ config CPU_FREQ_TABLE > > config CPU_FREQ_GOV_COMMON > > bool > > > > +config CPU_FREQ_BOOST_SW > > + bool > > Invisible is fine but this must be disabled by default and must > depend on thermal, rather than moving dependency on platform's > config.
The CPU_FREQ_BOOST_SW [1] is a generic flag (invisible).
I will add "default n" to it. It shall be used at all BOOST dependent #ifdefs (generic + platform).
Also I've introduced the ARM_EXYNOS_CPU_FREQ_BOOST_SW [2] config option. The CPU_FREQ_BOOST_SW option is selected from it.
Moreover the [2] depends on ARM_EXYNOS_CPUFREQ (which prevents from accidental enable/disable). And it selects automatically the EXYNOS_THERMAL, which is much better than depending only on THERMAL [3] (the generic framework).
Depending only on [3], results at situation where SW BOOST can be enabled at x86 or ARM target with only generic THERMAL support (which doesn't protect from overheating).
So the proposed solution: 1. Defines global flag [1] 2. This flag is selected only when dependencies for more HW close flag [2] are meet. 3. It is more natural to have Kconfig BOOST enable/disable checkbox at platform cpufreq driver (with description closer to HW). 4. Other ARCHs can easily define similar to [2] flag and by it select [1].
For me the approach proposed in this patch is more natural and provides high protection level from accidental SW boost enable.
-- Best regards,
Lukasz Majewski
Samsung R&D Institute Poland (SRPOL) | Linux Platform Group
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