Messages in this thread | | | From | Yongcai Huang <> | Subject | RE: [PATCH] ARM: imx: add cpuidle support for i.mx6ul | Date | Fri, 26 Aug 2016 03:33:58 +0000 |
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Best Regards! Anson Huang
> -----Original Message----- > From: Peter Chen [mailto:hzpeterchen@gmail.com] > Sent: 2016-08-25 3:09 PM > To: Yongcai Huang <anson.huang@nxp.com> > Cc: linux-arm-kernel@lists.infradead.org; lkml <linux-kernel@vger.kernel.org>; > Fabio Estevam <fabio.estevam@nxp.com>; shawnguo@kernel.org; > linux@armlinux.org.uk; kernel@pengutronix.de > Subject: Re: [PATCH] ARM: imx: add cpuidle support for i.mx6ul > > > > > Signed-off-by: Anson Huang <Anson.Huang@nxp.com> > > --- > > arch/arm/mach-imx/cpuidle-imx6sx.c | 10 ++++++++++ > > arch/arm/mach-imx/mach-imx6ul.c | 3 +++ > > 2 files changed, 13 insertions(+) > > > > diff --git a/arch/arm/mach-imx/cpuidle-imx6sx.c > > b/arch/arm/mach-imx/cpuidle-imx6sx.c > > index 41cdce6..b4fcc8ae 100644 > > --- a/arch/arm/mach-imx/cpuidle-imx6sx.c > > +++ b/arch/arm/mach-imx/cpuidle-imx6sx.c > > @@ -9,14 +9,21 @@ > > #include <linux/cpuidle.h> > > #include <linux/cpu_pm.h> > > #include <linux/module.h> > > +#include <linux/of.h> > > +#include <asm/cacheflush.h> > > #include <asm/cpuidle.h> > > #include <asm/suspend.h> > > > > #include "common.h" > > #include "cpuidle.h" > > > > +static bool pl310_available; > > + > > > > static int imx6sx_idle_finish(unsigned long val) { > > + /* check if need to flush internal L2 cache */ > > + if (!pl310_available) > > Just wondering why you need an extra variable here? > Calling of_find_compatible_node takes long time at that time? > > Peter >
Because cpu idle enter/exit is called very frequently, so calling of_find_compatible_node in every cpu idle thread is adding too many latency, I think adding a variable is better.
Anson
> > + flush_cache_all(); > > cpu_do_idle(); > > > > return 0; > > @@ -101,5 +108,8 @@ int __init imx6sx_cpuidle_init(void) > > imx_gpc_set_arm_power_up_timing(2, 1); > > imx_gpc_set_arm_power_down_timing(1, 1); > > > > + if (of_find_compatible_node(NULL, NULL, "arm,pl310-cache")) > > + pl310_available = true; > > + > > return cpuidle_register(&imx6sx_cpuidle_driver, NULL); } diff > > --git a/arch/arm/mach-imx/mach-imx6ul.c > > b/arch/arm/mach-imx/mach-imx6ul.c index c2cd61c..9c5e8f3 100644 > > --- a/arch/arm/mach-imx/mach-imx6ul.c > > +++ b/arch/arm/mach-imx/mach-imx6ul.c > > @@ -16,6 +16,7 @@ > > #include <asm/mach/map.h> > > > > #include "common.h" > > +#include "cpuidle.h" > > > > static void __init imx6ul_enet_clk_init(void) { @@ -80,6 +81,8 @@ > > static void __init imx6ul_init_irq(void) > > > > static void __init imx6ul_init_late(void) { > > + imx6sx_cpuidle_init(); > > + > > if (IS_ENABLED(CONFIG_ARM_IMX6Q_CPUFREQ)) { > > imx6_pm_opp_init(); > > platform_device_register_simple("imx6q-cpufreq", -1, > > NULL, 0); > > -- > > 1.9.1 > > > > > > _______________________________________________ > > linux-arm-kernel mailing list > > linux-arm-kernel@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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