[PATCH v2] ARM: imx: disable cpu in .cpu_kill hook
From: Shawn Guo <hidden>
Date: 2013-01-14 14:23:21
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
It's buggy to disable the cpu that is being hot-unplugged in .cpu_die hook which runs on the cpu itself. Instead, it should be done in .cpu_kill which runs on the thread (another cpu) that asks for shutting down the cpu. Move imx_enable_cpu(cpu, false) call into .cpu_kill hook, and leave the cpu to be hot-unplugged in WFI within .cpu_die, so that we can get a more stable cpu hot-plug operation. Signed-off-by: Shawn Guo <redacted> --- arch/arm/mach-imx/common.h | 1 + arch/arm/mach-imx/hotplug.c | 10 ++++++---- arch/arm/mach-imx/platsmp.c | 1 + 3 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/arm/mach-imx/common.h b/arch/arm/mach-imx/common.h
index 7191ab4..fa36fb8 100644
--- a/arch/arm/mach-imx/common.h
+++ b/arch/arm/mach-imx/common.h@@ -142,6 +142,7 @@ extern int imx6q_set_lpm(enum mxc_cpu_pwr_mode mode); extern void imx6q_clock_map_io(void); extern void imx_cpu_die(unsigned int cpu); +extern int imx_cpu_kill(unsigned int cpu); #ifdef CONFIG_PM extern void imx6q_pm_init(void);
diff --git a/arch/arm/mach-imx/hotplug.c b/arch/arm/mach-imx/hotplug.c
index 3dec962..7bc5fe1 100644
--- a/arch/arm/mach-imx/hotplug.c
+++ b/arch/arm/mach-imx/hotplug.c@@ -46,9 +46,11 @@ static inline void cpu_enter_lowpower(void) void imx_cpu_die(unsigned int cpu) { cpu_enter_lowpower(); - imx_enable_cpu(cpu, false); + cpu_do_idle(); +} - /* spin here until hardware takes it down */ - while (1) - ; +int imx_cpu_kill(unsigned int cpu) +{ + imx_enable_cpu(cpu, false); + return 1; }
diff --git a/arch/arm/mach-imx/platsmp.c b/arch/arm/mach-imx/platsmp.c
index 3777b80..66fae88 100644
--- a/arch/arm/mach-imx/platsmp.c
+++ b/arch/arm/mach-imx/platsmp.c@@ -92,5 +92,6 @@ struct smp_operations imx_smp_ops __initdata = { .smp_boot_secondary = imx_boot_secondary, #ifdef CONFIG_HOTPLUG_CPU .cpu_die = imx_cpu_die, + .cpu_kill = imx_cpu_kill, #endif };
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1.7.9.5