ARM: 5849/1: 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>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/oprofile/op_model_v7.c b/arch/arm/oprofile/op_model_v7.c
index f20295f..2088a6c 100644 (file)
--- 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++) {