From mboxrd@z Thu Jan 1 00:00:00 1970 From: kever.yang@rock-chips.com (Kever Yang) Date: Fri, 05 Jun 2015 14:32:27 +0800 Subject: [PATCH 2/3] ARM: rockchip: ensure CPU to enter WIF state In-Reply-To: <1433479677-18086-3-git-send-email-wxt@rock-chips.com> References: <1433479677-18086-1-git-send-email-wxt@rock-chips.com> <1433479677-18086-3-git-send-email-wxt@rock-chips.com> Message-ID: <5571427B.1040406@rock-chips.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Caesar, Subject typo WIF/WFI. On 06/05/2015 12:47 PM, Caesar Wang wrote: > In idle mode, core1/2/3 of Cortex-A17 should be either power off or in > WFI/WFE state. > we can delay 1ms to ensure the CPU enter WFI state. > > Signed-off-by: Caesar Wang > --- > > arch/arm/mach-rockchip/platsmp.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/arm/mach-rockchip/platsmp.c b/arch/arm/mach-rockchip/platsmp.c > index 1230d3d..978c357 100644 > --- a/arch/arm/mach-rockchip/platsmp.c > +++ b/arch/arm/mach-rockchip/platsmp.c > @@ -316,6 +316,9 @@ static void __init rockchip_smp_prepare_cpus(unsigned int max_cpus) > #ifdef CONFIG_HOTPLUG_CPU > static int rockchip_cpu_kill(unsigned int cpu) > { > + /* ensure CPU can enter the WFI/WFE state */ > + mdelay(1); > + Does it matter if core is not in WFI state when we want to power down it? Thanks, - Kever > pmu_set_power_domain(0 + cpu, false); > return 1; > }