From: jpihet@mvista.com (Jean Pihet)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARMv7: fix Oprofile events count
Date: Mon, 14 Dec 2009 12:40:11 +0100 [thread overview]
Message-ID: <1260790811.8106.2.camel@def-laptop> (raw)
Hi,
Here is a patch that fixes the oprofile events count.
If it is OK I will submit it to the patch system.
Any thought?
Regards,
Jean
---
ARMv7: fix Oprofile events count
On Oprofile ARMv7 the PMNC_D bit was set to lower the PMU IRQs
and so to decrease the risk of errata #628216 from appearing.
The effect of setting the PMNC_D bit is that the CCNT counter
is divided by 64, making the program counter events count
inaccurate.
The new OMAP3 r4 cores should have that errata fixed.
The PMNC_D bit should not be set, this patch fixes it.
Signed-off-by: Jean Pihet <jpihet@mvista.com>
diff --git a/arch/arm/oprofile/op_model_v7.c
b/arch/arm/oprofile/op_model_v7.c
index f20295f..2088a6c 100644
--- a/arch/arm/oprofile/op_model_v7.c
+++ b/arch/arm/oprofile/op_model_v7.c
@@ -191,12 +191,8 @@ int armv7_setup_pmnc(void)
return -EBUSY;
}
- /*
- * Initialize & Reset PMNC: C bit, D bit and P bit.
- * Note: Using a slower count for CCNT (D bit: divide by 64)
results
- * in a more stable system
- */
- armv7_pmnc_write(PMNC_P | PMNC_C | PMNC_D);
+ /* Initialize & Reset PMNC: C bit and P bit */
+ armv7_pmnc_write(PMNC_P | PMNC_C);
for (cnt = CCNT; cnt < CNTMAX; cnt++) {
next reply other threads:[~2009-12-14 11:40 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-14 11:40 Jean Pihet [this message]
2009-12-14 12:28 ` [PATCH] ARMv7: fix Oprofile events count Gadiyar, Anand
2009-12-14 12:38 ` Jean Pihet
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