oprofile and ARM A9 hardware counter

[stephane eranian]

2012/1/27 Will Deacon <will.deacon at arm.com>:
> Mans,
>
> On Fri, Jan 27, 2012 at 12:56:35PM +0000, Måns Rullgård wrote:
>> Will Deacon <will.deacon at arm.com> writes:
>> > Did this lead anywhere in the end? It seems as though Ming Lei has a working
>> > setup but Stephane is unable to replicate it, despite applying the necessary
>> > patches and trying an updated bootloader.
>>
>> With the patches listed above plus the one in [1], I get PMU interrupts.
>> However, unless I restrict the profiled process to one CPU
>> (taskset 1 perf record ...), I get a panic in armpmu_event_update() with
>> the 'event' argument being null when called from armv7pmu_handle_irq().
>>
>> [1] http://article.gmane.org/gmane.linux.ports.arm.omap/69696
>
Ok, I am recompiling the kernel for this one line fix:

--- a/arch/arm/mach-omap2/clockdomains44xx_data.c
+++ b/arch/arm/mach-omap2/clockdomains44xx_data.c
@@ -390,7 +390,7 @@ static struct clockdomain emu_sys_44xx_clkdm = {
       .prcm_partition   = OMAP4430_PRM_PARTITION,
       .cm_inst          = OMAP4430_PRM_EMU_CM_INST,
       .clkdm_offs       = OMAP4430_PRM_EMU_CM_EMU_CDOFFS,
-       .flags            = CLKDM_CAN_HWSUP,
+       .flags            = CLKDM_CAN_SWSUP,
 };