[PATCH] ARM: automatically select OMAP3_PMU if we try to use perf on OMAP3
From: arnd@arndb.de (Arnd Bergmann)
Date: 2011-06-30 13:27:02
On Thursday 30 June 2011, Bryan Wu wrote:
On Tue, Jun 28, 2011 at 9:57 PM, Will Deacon [off-list ref] wrote:
quoted hunk ↗ jump to hunk
quoted
This issue has been discussed on the list in the past and I still think that it would be better for your config to select OMAP3_EMU explicitly. If we do that here unconditionally then we end up also bringing in OC_ETM which isn't something that sounds like a good idea (may have implications for power consumption in production hardware?).I quite understand your concern. How about this one? ----diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 2fd0911..e53f9e4 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig@@ -1084,10 +1084,10 @@ 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 + select OMAP3_EMU if (PERF_EVENTS && ARCH_OMAP3) config MULTI_IRQ_HANDLER bool
As far as I can tell, it still has the same issue. I think the existing code is better. If you want to support HW_PERF_EVENTS on OMAP3, just turn on OMAP3_EMU. Where's the problem with that? In general, specifying clear dependencies is preferred over 'select' statements, which are the equivalent to the 'comefrom' statement in programming languages [1]. Arnd [1] http://en.wikipedia.org/wiki/COMEFROM