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From: John Stultz <john.stultz@linaro.org>
To: LKML <linux-kernel@vger.kernel.org>
Cc: "Arve Hjønnevåg" <arve@android.com>,
	"Russell King" <linux@arm.linux.org.uk>,
	"Paul Gortmaker" <paul.gortmaker@windriver.com>,
	"Alexander Shishkin" <alexander.shishkin@linux.intel.com>,
	"Mathieu Poirier" <mathieu.poirier@linaro.org>,
	"John Stultz" <john.stultz@linaro.org>
Subject: [PATCH 09/15] ARM: etm: Power down etm(s) when tracing is not enabled
Date: Tue, 12 Jun 2012 19:01:27 -0700	[thread overview]
Message-ID: <1339552887-17204-10-git-send-email-john.stultz@linaro.org> (raw)
In-Reply-To: <1339552887-17204-1-git-send-email-john.stultz@linaro.org>

From: Arve Hjønnevåg <arve@android.com>

Without this change a saw an 18% increase in idle power consumption
on one deivce when trace support is compiled into the kernel. Now
I see the same increase only when tracing.

CC: Russell King <linux@arm.linux.org.uk>
CC: Paul Gortmaker <paul.gortmaker@windriver.com>
CC: Alexander Shishkin <alexander.shishkin@linux.intel.com>
CC: Mathieu Poirier <mathieu.poirier@linaro.org>

Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 arch/arm/kernel/etm.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/kernel/etm.c b/arch/arm/kernel/etm.c
index e3309ea..66bf592 100644
--- a/arch/arm/kernel/etm.c
+++ b/arch/arm/kernel/etm.c
@@ -200,7 +200,7 @@ static int trace_stop_etm(struct tracectx *t, int id)
 
 	etm_unlock(t, id);
 
-	etm_writel(t, id, 0x440, ETMR_CTRL);
+	etm_writel(t, id, 0x441, ETMR_CTRL);
 	while (!(etm_readl(t, id, ETMR_CTRL) & ETMCTRL_PROGRAM) && --timeout)
 		;
 	if (!timeout) {
@@ -739,7 +739,7 @@ static int __devinit etm_probe(struct amba_device *dev, const struct amba_id *id
 	(void)etm_readl(&tracer, t->etm_regs_count, ETMMR_OSSRR);
 
 	t->ncmppairs = etm_readl(t, t->etm_regs_count, ETMR_CONFCODE) & 0xf;
-	etm_writel(t, t->etm_regs_count, 0x440, ETMR_CTRL);
+	etm_writel(t, t->etm_regs_count, 0x441, ETMR_CTRL);
 	etm_writel(t, t->etm_regs_count, new_count, ETMR_TRACEIDR);
 	etm_lock(t, t->etm_regs_count);
 
-- 
1.7.3.2.146.gca209


  parent reply	other threads:[~2012-06-13  2:02 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-13  2:01 [PATCH 00/15][RFC] Android ETM driver changes John Stultz
2012-06-13  2:01 ` [PATCH 01/15] ARM: etm: Don't require clock control John Stultz
2012-06-13  8:33   ` Paul Mundt
2012-06-13 23:09     ` John Stultz
2012-06-13  2:01 ` [PATCH 02/15] ARM: etm: Don't limit tracing to only non-secure code John Stultz
2012-06-13  2:01 ` [PATCH 03/15] ARM: etm: Don't try to clear the buffer full status after reading the buffer John Stultz
2012-06-13  2:01 ` [PATCH 04/15] ARM: etm: Allow range selection John Stultz
2012-06-13  2:01 ` [PATCH 05/15] ARM: etm: Configure data tracing John Stultz
2012-06-13  2:01 ` [PATCH 06/15] ARM: etm: Add some missing locks and error checks John Stultz
2012-06-13  2:01 ` [PATCH 07/15] ARM: etm: Return the entire trace buffer if it is empty after reset John Stultz
2012-06-13  2:01 ` [PATCH 08/15] ARM: etm: Support multiple ETMs/PTMs John Stultz
2012-06-13  2:01 ` John Stultz [this message]
2012-06-28 16:13 ` [PATCH 00/15][RFC] Android ETM driver changes Linus Walleij
2012-06-29 20:25   ` John Stultz
2012-06-20 22:47 [PATCH 00/15] " John Stultz
2012-06-20 22:47 ` [PATCH 09/15] ARM: etm: Power down etm(s) when tracing is not enabled John Stultz
2012-06-28 16:01   ` Linus Walleij

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