From mboxrd@z Thu Jan 1 00:00:00 1970 From: shawn.guo@freescale.com (Shawn Guo) Date: Mon, 21 Jul 2014 15:45:54 +0800 Subject: [PATCH 2/3] ARM: smp_scu: enable SCU standby support In-Reply-To: <1405928755-19413-1-git-send-email-shawn.guo@freescale.com> References: <1405928755-19413-1-git-send-email-shawn.guo@freescale.com> Message-ID: <1405928755-19413-3-git-send-email-shawn.guo@freescale.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org With SCU standby enabled, SCU CLK will be turned off when all processors are in WFI mode. And the clock will be turned on when any processor leaves WFI mode. This behavior should be preferable in terms of power efficiency of system idle. So let's set the SCU standby bit to enable the support in function scu_enable(). Signed-off-by: Shawn Guo --- arch/arm/kernel/smp_scu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm/kernel/smp_scu.c b/arch/arm/kernel/smp_scu.c index c947508f84e6..9f29d167d02c 100644 --- a/arch/arm/kernel/smp_scu.c +++ b/arch/arm/kernel/smp_scu.c @@ -18,6 +18,7 @@ #define SCU_CTRL 0x00 #define SCU_ENABLE (1 << 0) +#define SCU_STANDBY_ENABLE (1 << 5) #define SCU_CONFIG 0x04 #define SCU_CPU_STATUS 0x08 #define SCU_INVALIDATE 0x0c @@ -54,7 +55,7 @@ void scu_enable(void __iomem *scu_base) if (scu_ctrl & SCU_ENABLE) return; - scu_ctrl |= SCU_ENABLE; + scu_ctrl |= SCU_ENABLE | SCU_STANDBY_ENABLE; writel_relaxed(scu_ctrl, scu_base + SCU_CTRL); /* -- 1.9.1