From mboxrd@z Thu Jan 1 00:00:00 1970 From: jon-hunter@ti.com (Jon Hunter) Date: Fri, 13 Jul 2012 09:07:41 -0500 Subject: [PATCH V2 08/10] ARM: OMAP4: Prevent EMU power domain transitioning to OFF when in-use In-Reply-To: <20120713140021.GS18079@mudshark.cambridge.arm.com> References: <1339104132-26885-1-git-send-email-jon-hunter@ti.com> <1339104132-26885-9-git-send-email-jon-hunter@ti.com> <500028B3.1040309@ti.com> <20120713140021.GS18079@mudshark.cambridge.arm.com> Message-ID: <50002BAD.3010600@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Will, On 07/13/2012 09:00 AM, Will Deacon wrote: > Jon, > > [cutting out realms of context!] Thanks! My inbox thanks you too ;-) > On Fri, Jul 13, 2012 at 02:54:59PM +0100, Jon Hunter wrote: >> Another proposal I also thought of is re-working the flags to describe >> the HW mode to be used when turning on the CLKDM, when the CLKDM is >> active and when the CLKDM is shut down. So instead of saying what modes >> the CLKDM supports, specify what modes should be used for pre-ON (i.e. >> turn ON), ON and OFF. Right now software is trying to decide for us by >> what is available (which is ideal) but makes working around such nuances >> a little more painful. >> >> By the way, I did do some testing on OMAP3, but I don't recall now >> whether I was having such problems with OMAP3. I need to go back and >> test perf again on OMAP3 to see if such a flag is needed. > > If you do test on OMAP3, please kill the OMAP3_EMU option as I think this > has the effect of keeping the EMU power domain up via the etm code (look at > etb_probe). > > Will > > ---8<--- > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index a91009c..d02054c 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -1139,8 +1139,7 @@ config XSCALE_PMU > default y > > config CPU_HAS_PMU > - depends on (CPU_V6 || CPU_V6K || CPU_V7 || XSCALE_PMU) && \ > - (!ARCH_OMAP3 || OMAP3_EMU) > + depends on (CPU_V6 || CPU_V6K || CPU_V7 || XSCALE_PMU) > default y > bool Ah-ha! May be this is why is worked without issue. I will look at that and check the power states. I must admit that my testing was quick to ensure no breakages but no thorough to check what was going on with power. Cheers Jon