From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758141Ab2FTWsT (ORCPT ); Wed, 20 Jun 2012 18:48:19 -0400 Received: from e39.co.us.ibm.com ([32.97.110.160]:47047 "EHLO e39.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757935Ab2FTWsJ (ORCPT ); Wed, 20 Jun 2012 18:48:09 -0400 From: John Stultz To: LKML Cc: =?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= , Russell King , Paul Gortmaker , Alexander Shishkin , John Stultz Subject: [PATCH 09/15] ARM: etm: Power down etm(s) when tracing is not enabled Date: Wed, 20 Jun 2012 18:47:41 -0400 Message-Id: <1340232467-6023-10-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1340232467-6023-1-git-send-email-john.stultz@linaro.org> References: <1340232467-6023-1-git-send-email-john.stultz@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12062022-4242-0000-0000-0000020E4156 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arve Hjønnevåg 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 CC: Paul Gortmaker CC: Alexander Shishkin Acked-by: Alexander Shishkin Signed-off-by: Arve Hjønnevåg Signed-off-by: John Stultz --- arch/arm/kernel/etm.c | 4 ++-- 1 file 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); -- 1.7.9.5