Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH, RFC 02/22] cpufreq: ARM_DT_BL_CPUFREQ needs ARM_CPU_TOPOLOGY | Date | Fri, 03 May 2013 14:15:57 +0200 |
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On Friday, May 03, 2013 10:21:45 AM Viresh Kumar wrote: > On 2 May 2013 20:46, Arnd Bergmann <arnd@arndb.de> wrote: > > The big.LITTLE cpufreq driver uses the CPU topology API, which > > needs to be reflected in Kconfig to prevent broken configurations. > > > > warning: (ARM_DT_BL_CPUFREQ) selects ARM_BIG_LITTLE_CPUFREQ which > > has unmet direct dependencies (ARCH_HAS_CPUFREQ && CPU_FREQ && ARM && ARM_CPU_TOPOLOGY) > > > > Cc: Rafael J. Wysocki <rjw@sisk.pl> > > Cc: Viresh Kumar <viresh.kumar@linaro.org> > > Cc: cpufreq@vger.kernel.org > > Cc: linux-pm@vger.kernel.org > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > --- > > drivers/cpufreq/Kconfig.arm | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm > > index f3af18b..3fd6bdf 100644 > > --- a/drivers/cpufreq/Kconfig.arm > > +++ b/drivers/cpufreq/Kconfig.arm > > @@ -10,6 +10,7 @@ config ARM_DT_BL_CPUFREQ > > tristate "Generic ARM big LITTLE CPUfreq driver probed via DT" > > select ARM_BIG_LITTLE_CPUFREQ > > depends on OF && HAVE_CLK > > + depends on ARM_CPU_TOPOLOGY > > help > > This enables the Generic CPUfreq driver for ARM big.LITTLE platform. > > This gets frequency tables from DT. > > This Kconfig thing has always been confusing to me. This is how the code looks > currently. > > config ARM_BIG_LITTLE_CPUFREQ > tristate > depends on ARM_CPU_TOPOLOGY > > config ARM_DT_BL_CPUFREQ > tristate "Generic ARM big LITTLE CPUfreq driver probed via DT" > select ARM_BIG_LITTLE_CPUFREQ > depends on OF && HAVE_CLK > help > This enables the Generic CPUfreq driver for ARM big.LITTLE platform. > This gets frequency tables from DT. > > Because all ARM big LITTLE cpufreq stuff have dependency on > ARM_CPU_TOPOLOGY, i have added dependency at a common place. So that > we don't end up adding this in every glue layer driver. How should this be done?
First, there's no rule of thumb here as far as I can say.
In this particular case I think it is OK to make both ARM_DT_BL_CPUFREQ and ARM_BIG_LITTLE_CPUFREQ depend on ARM_CPU_TOPOLOGY, because (in theory?) the latter may be set without the former (unless you want to make ARM_DT_BL_CPUFREQ depend on ARM_BIG_LITTLE_CPUFREQ, but then it may be kind of confusing to users).
Thanks, Rafael
-- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.
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