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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>
Jean PIHET 15 năm trước cách đây
mục cha
commit
3321c2bcea
1 tập tin đã thay đổi với 2 bổ sung6 xóa
  1. 2 6
      arch/arm/oprofile/op_model_v7.c

+ 2 - 6
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++) {