oprofile and ARM A9 hardware counter

[Ming Lei]

Hi Will and stephane,

On Wed, Jan 18, 2012 at 12:18 PM, Ming Lei <ming.lei at canonical.com> wrote:
> Hi stephane & Will,
>
> On Tue, Jan 10, 2012 at 8:46 AM, stephane eranian
> <eranian at googlemail.com> wrote:
>> See the dmesg from my 3.2 kernel:
>>
>>
>> [    0.000000] Booting Linux on physical CPU 0[    0.000000]

But if you test omap4 perf against -next kernel, pmu won't work because
the commit[1] may put 'emu_sys_clkdm'  clock domain into HW_AUTO mode,
so writing pmu register may not take effect.

I have found  the similar problem on cam clock domain before[2].
CD_EMU is very simliar with CD_CAM in the point below:

	CD_EMU has no static or module wake-up dependency with any other clock
	domain of the device.[3]

So the patch[4] can make omap4 pmu work on -next tree.

Shilimkar, care to comment on the patch[4]?

thanks,
--
Ming Lei

[1], commit 3c50729b3fa1cd8ca1f347e6caf1081204cf1a7c
Author: Santosh Shilimkar <santosh.shilimkar at ti.com>
Date:   Wed Jan 5 22:03:17 2011 +0530

   ARM: OMAP4: PM: Initialise all the clockdomains to supported states

   Initialise hardware supervised mode for all clockdomains if it's
   supported. Initiate sleep transition for other clockdomains,
   if they are not being used.

[2], http://www.spinics.net/lists/linux-omap/msg61911.html

[3], 3.6.12.3 of OMAP4 TRM

[4],
diff --git a/arch/arm/mach-omap2/clockdomains44xx_data.c
b/arch/arm/mach-omap2/clockdomains44xx_data.c
index 9299ac2..41d2260 100644
--- 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,
 };

 static struct clockdomain l3_dma_44xx_clkdm = {