From mboxrd@z Thu Jan 1 00:00:00 1970 From: pankaj.dubey@samsung.com (Pankaj Dubey) Date: Fri, 14 Nov 2014 11:40:06 +0530 Subject: [PATCH] ARM: b.L: fix unmet dependency for CPU_PM In-Reply-To: References: <1415857098-16928-1-git-send-email-pankaj.dubey@samsung.com> <20141113174837.GB4042@n2100.arm.linux.org.uk> Message-ID: <001401cfffd1$ae9df930$0bd9eb90$@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org +CC: Colin Cross, James Hogan On Thursday, November 13, 2014 11:30 PM, Nicolas Pitre wrote: > To: Russell King - ARM Linux > Cc: Pankaj Dubey; linux-arm-kernel at lists.infradead.org; linux- > kernel at vger.kernel.org > Subject: Re: [PATCH] ARM: b.L: fix unmet dependency for CPU_PM > > On Thu, 13 Nov 2014, Russell King - ARM Linux wrote: > > > On Thu, Nov 13, 2014 at 12:44:22PM -0500, Nicolas Pitre wrote: > > > On Thu, 13 Nov 2014, Pankaj Dubey wrote: > > > > > > > If BL_SWITCHER is enabled but SUSPEND and CPU_IDLE is not enabled > > > > we are getting following config warning. > > > > > > > > warning: (BL_SWITCHER) selects CPU_PM which has unmet direct > > > > dependencies (SUSPEND || CPU_IDLE) > > > > > > > > So BL_SWITCHER should enable CPU_PM only if either of SUSPEND or > > > > CPU_IDLE is selected. > > > > > > > > Signed-off-by: Pankaj Dubey > > > > --- > > > > arch/arm/Kconfig | 2 +- > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index > > > > 9d580d0..fe3d969 100644 > > > > --- a/arch/arm/Kconfig > > > > +++ b/arch/arm/Kconfig > > > > @@ -1417,7 +1417,7 @@ config BL_SWITCHER > > > > bool "big.LITTLE switcher support" > > > > depends on BIG_LITTLE && MCPM && HOTPLUG_CPU > > > > select ARM_CPU_SUSPEND > > > > - select CPU_PM > > > > + select CPU_PM if (SUSPEND || CPU_IDLE) > > > > > > NAK. You just broke the code by doing this. CPU_PM is a requirement > > > here. The dependencies for CPU_PM is lacking. > > OK, got it. Even though compilation worked, but as you mentioned by doing this way bL_switcher functionality may broke. > > Is there any real technical reason that CPU_PM depends on SUSPEND || > > CPU_IDLE ? If not, those dependencies should be killed. > > Those dependencies look artificial to me. > For me also it looks like these dependencies are artificial. As far as I can see CONFIG_CPU_PM compiles following two files 1: kernel/cpu_pm.c - I can't see any dependency of SUSPEND or CPU_IDLE in this file. 2: arch/mips/kernel/pm.c: A quick look does not show any dependency of SUSPEND or CPU_IDLE here too. So for me it looks like it is OK to kill these dependencies of CPU_PM. Still safer side I am CCing this to author of these files for confirmation. Thanks, Pankaj Dubey > > Nicolas