On pią, 2014-04-04 at 11:48 +0200, Daniel Lezcano wrote: > The following driver is for exynos4210. I did not yet finished the other boards, so > I created a specific driver for 4210 which could be merged later. > > The driver is based on Colin Cross's driver found at: > > https://android.googlesource.com/kernel/exynos/+/e686b1ec67423c40b4fdf811f9a4dfa3b393a010%5E%5E!/ > > This one was based on a 3.4 kernel and an old API. > > It has been refreshed, simplified and based on the recent code cleanup I sent > today. > > The AFTR could be entered when all the cpus (except cpu0) are down. In order to > reach this situation, the couple idle states are used. > > There is a sync barrier at the entry and the exit of the low power function. So > all cpus will enter and exit the function at the same time. > > At this point, CPU0 knows the other cpu will power down itself. CPU0 waits for > the CPU1 to be powered down and then initiate the AFTR power down sequence. > > No interrupts are handled by CPU1, this is why we switch to the timer broadcast > even if the local timer is not impacted by the idle state. > > When CPU0 wakes up, it powers up CPU1 and waits for it to boot. Then they both > exit the idle function. > > This driver allows the exynos4210 to have the same power consumption at idle > time than the one when we have to unplug CPU1 in order to let CPU0 to reach > the AFTR state. > > This patch is a RFC because, we have to find a way to remove the macros > definitions and cpu powerdown function without pulling the arch dependent > headers. > > Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> > --- > arch/arm/mach-exynos/common.c | 11 +- > drivers/cpuidle/Kconfig.arm | 8 ++ > drivers/cpuidle/Makefile | 1 + > drivers/cpuidle/cpuidle-exynos4210.c | 226 ++++++++++++++++++++++++++++++++++ > 4 files changed, 245 insertions(+), 1 deletion(-) > create mode 100644 drivers/cpuidle/cpuidle-exynos4210.c (...) > diff --git a/drivers/cpuidle/cpuidle-exynos4210.c b/drivers/cpuidle/cpuidle-exynos4210.c > new file mode 100644 > index 0000000..56f6d51 > --- /dev/null > +++ b/drivers/cpuidle/cpuidle-exynos4210.c > @@ -0,0 +1,226 @@ > +/* > + * Copyright (c) 2014 Samsung Electronics Co., Ltd. > + * http://www.samsung.com > + * > + * Copyright (c) 2014 Linaro : Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> > + * http://www.linaro.org > + * > + * Based on the work of Colin Cross <ccross@xxxxxxxxxxx> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + */ > + > +#include <linux/cpuidle.h> > +#include <linux/cpu_pm.h> > +#include <linux/io.h> > +#include <linux/platform_device.h> > + > +#include <asm/proc-fns.h> > +#include <asm/suspend.h> > +#include <asm/cpuidle.h> > + > +#include <plat/pm.h> > +#include <plat/cpu.h> > +#include <plat/map-base.h> > +#include <plat/map-s5p.h> > + > +static atomic_t exynos_idle_barrier; Hi, Shouldn't the exynos_idle_barrier be initialized here? I know you sent the patch almost 2 months ago but I stomped on this while testing it on Exynos3250. Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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