path: root/arch
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authorMagnus Damm <>2012-05-10 14:57:22 +0900
committerRafael J. Wysocki <>2012-05-12 22:13:38 +0200
commitb759bd114e27fbb940fb44fd16552e8f4acd831e (patch)
treeaabfb18091281cc5af1df1e76a5ebdbc7bcd5a75 /arch
parent173e2fec4d9e950ee5e4bba272091e248a961c98 (diff)
ARM / mach-shmobile: r8a7779 SMP TWD boot regression fix
Fix SMP TWD boot regression on r8a7779 based platforms caused by: 4200b16 ARM: shmobile: convert to twd_local_timer_register() interface After the merge of the above commit it has been impossible to boot r8a7779 based SoCs with SMP enabled and CONFIG_HAVE_ARM_TWD=y. The kernel crashes at smp_init_cpus() timing which is before the console has been initialized, so to the user this looks like a kernel lock up without any particular error message. This patch fixes the regression on r8a7779 by moving the TWD registration code from smp_init_cpus() to sys_timer->init() time. Signed-off-by: Magnus Damm <> Acked-by: Marc Zyngier <> Signed-off-by: Rafael J. Wysocki <>
Diffstat (limited to 'arch')
3 files changed, 12 insertions, 1 deletions
diff --git a/arch/arm/mach-shmobile/include/mach/common.h b/arch/arm/mach-shmobile/include/mach/common.h
index 83ad3fe0a75f..18ac8251a26a 100644
--- a/arch/arm/mach-shmobile/include/mach/common.h
+++ b/arch/arm/mach-shmobile/include/mach/common.h
@@ -82,5 +82,6 @@ extern int r8a7779_platform_cpu_kill(unsigned int cpu);
extern void r8a7779_secondary_init(unsigned int cpu);
extern int r8a7779_boot_secondary(unsigned int cpu);
extern void r8a7779_smp_prepare_cpus(void);
+extern void r8a7779_register_twd(void);
#endif /* __ARCH_MACH_COMMON_H */
diff --git a/arch/arm/mach-shmobile/setup-r8a7779.c b/arch/arm/mach-shmobile/setup-r8a7779.c
index 12c6f529ab89..e98e46f6cf55 100644
--- a/arch/arm/mach-shmobile/setup-r8a7779.c
+++ b/arch/arm/mach-shmobile/setup-r8a7779.c
@@ -262,10 +262,14 @@ void __init r8a7779_add_standard_devices(void)
+/* do nothing for !CONFIG_SMP or !CONFIG_HAVE_TWD */
+void __init __weak r8a7779_register_twd(void) { }
static void __init r8a7779_earlytimer_init(void)
+ r8a7779_register_twd();
void __init r8a7779_add_early_devices(void)
diff --git a/arch/arm/mach-shmobile/smp-r8a7779.c b/arch/arm/mach-shmobile/smp-r8a7779.c
index b62e19d4c9af..6d1d0238cbf7 100644
--- a/arch/arm/mach-shmobile/smp-r8a7779.c
+++ b/arch/arm/mach-shmobile/smp-r8a7779.c
@@ -64,8 +64,15 @@ static void __iomem *scu_base_addr(void)
static DEFINE_SPINLOCK(scu_lock);
static unsigned long tmp;
static DEFINE_TWD_LOCAL_TIMER(twd_local_timer, 0xf0000600, 29);
+void __init r8a7779_register_twd(void)
+ twd_local_timer_register(&twd_local_timer);
static void modify_scu_cpu_psr(unsigned long set, unsigned long clr)
void __iomem *scu_base = scu_base_addr();
@@ -84,7 +91,6 @@ unsigned int __init r8a7779_get_core_count(void)
void __iomem *scu_base = scu_base_addr();
- shmobile_twd_init(&twd_local_timer);
return scu_get_core_count(scu_base);