From: Arve Hjønnevåg Date: Thu, 24 Feb 2011 00:51:58 +0000 (-0800) Subject: ARM: etm: Power down etm(s) when tracing is not enabled X-Git-Tag: firefly_0821_release~7613^2~631 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=38dfc33b206dc608a8080630c6689ff3556e95e9;p=firefly-linux-kernel-4.4.55.git ARM: etm: Power down etm(s) when tracing is not enabled 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. Change-Id: I21bb5ecf1b7d29ce3790ceeb5323409cc22d5a3b Signed-off-by: Arve Hjønnevåg --- diff --git a/arch/arm/kernel/etm.c b/arch/arm/kernel/etm.c index 82e6d38fb93d..496b8b84e455 100644 --- a/arch/arm/kernel/etm.c +++ b/arch/arm/kernel/etm.c @@ -199,7 +199,7 @@ 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) { @@ -738,7 +738,7 @@ 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);