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linux-next/drivers/cpuidle/cpuidle-exynos.c
Tomasz Figa 01601b3495 ARM: EXYNOS: Fix suspend/resume sequences
Due to recent consolidation of Exynos suspend and cpuidle code, some
parts of suspend and resume sequences are executed two times, once from
exynos_pm_syscore_ops and then from exynos_cpu_pm_notifier() and thus it
breaks suspend, at least on Exynos4-based boards. In addition, simple
core power down from a cpuidle driver could, in case of CPU 0 could
result in calling functions that are specific to suspend and deeper idle
states.

This patch fixes the issue by moving those operations outside the CPU PM
notifier into suspend and AFTR code paths. This leads to a bit of code
duplication, but allows additional code simplification, so in the end
more code is removed than added.

Fixes: 85f9f90808 ("ARM: EXYNOS: Use the cpu_pm notifier for pm")
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Olof Johansson <olof@lixom.net>
Cc: arm@kernel.org
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
[b.zolnierkie: ported patch over current changes]
[b.zolnierkie: fixed exynos_aftr_finisher() return value]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
2014-08-09 08:24:36 -07:00

83 lines
1.8 KiB
C

/* linux/arch/arm/mach-exynos/cpuidle.c
*
* Copyright (c) 2011 Samsung Electronics Co., Ltd.
* http://www.samsung.com
*
* 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/export.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <asm/proc-fns.h>
#include <asm/suspend.h>
#include <asm/cpuidle.h>
static void (*exynos_enter_aftr)(void);
static int exynos_enter_lowpower(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
int new_index = index;
/* AFTR can only be entered when cores other than CPU0 are offline */
if (num_online_cpus() > 1 || dev->cpu != 0)
new_index = drv->safe_state_index;
if (new_index == 0)
return arm_cpuidle_simple_enter(dev, drv, new_index);
exynos_enter_aftr();
return new_index;
}
static struct cpuidle_driver exynos_idle_driver = {
.name = "exynos_idle",
.owner = THIS_MODULE,
.states = {
[0] = ARM_CPUIDLE_WFI_STATE,
[1] = {
.enter = exynos_enter_lowpower,
.exit_latency = 300,
.target_residency = 100000,
.flags = CPUIDLE_FLAG_TIME_VALID,
.name = "C1",
.desc = "ARM power down",
},
},
.state_count = 2,
.safe_state_index = 0,
};
static int exynos_cpuidle_probe(struct platform_device *pdev)
{
int ret;
exynos_enter_aftr = (void *)(pdev->dev.platform_data);
ret = cpuidle_register(&exynos_idle_driver, NULL);
if (ret) {
dev_err(&pdev->dev, "failed to register cpuidle driver\n");
return ret;
}
return 0;
}
static struct platform_driver exynos_cpuidle_driver = {
.probe = exynos_cpuidle_probe,
.driver = {
.name = "exynos_cpuidle",
.owner = THIS_MODULE,
},
};
module_platform_driver(exynos_cpuidle_driver);