Commit 3321c2bc authored Dec 15, 2009 by Jean PIHET Committed by Russell King Dec 22, 2009

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>

parent cdd90fb5

arch/arm/oprofile/op_model_v7.c

+2 −6

Original line number	Diff line number	Diff line
		@@ -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++) {