1 files changed, 16 insertions, 6 deletions

diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index 3cd2f70d1c18..88be966d3e61 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -66,6 +66,7 @@ EXPORT_SYMBOL(cpu_sibling_map);
 cpumask_t cpu_core_map[NR_CPUS] __read_mostly;
 EXPORT_SYMBOL(cpu_core_map);
 
+static DECLARE_COMPLETION(cpu_starting);
 static DECLARE_COMPLETION(cpu_running);
 
 /*
@@ -374,6 +375,12 @@ asmlinkage void start_secondary(void)
         cpumask_set_cpu(cpu, &cpu_coherent_mask);
         notify_cpu_starting(cpu);
 
+        /* Notify boot CPU that we're starting & ready to sync counters */
+        complete(&cpu_starting);
+
+        synchronise_count_slave(cpu);
+
+        /* The CPU is running and counters synchronised, now mark it online */
         set_cpu_online(cpu, true);
 
         set_cpu_sibling_map(cpu);
@@ -381,8 +388,11 @@ asmlinkage void start_secondary(void)
 
         calculate_cpu_foreign_map();
 
+        /*
+         * Notify boot CPU that we're up & online and it can safely return
+         * from __cpu_up
+         */
         complete(&cpu_running);
-        synchronise_count_slave(cpu);
 
         /*
          * irq will be enabled in ->smp_finish(), enabling it too early
@@ -445,17 +455,17 @@ int __cpu_up(unsigned int cpu, struct task_struct *tidle)
         if (err)
                 return err;
 
-        /*
-         * We must check for timeout here, as the CPU will not be marked
-         * online until the counters are synchronised.
-         */
-        if (!wait_for_completion_timeout(&cpu_running,
+        /* Wait for CPU to start and be ready to sync counters */
+        if (!wait_for_completion_timeout(&cpu_starting,
                                          msecs_to_jiffies(1000))) {
                 pr_crit("CPU%u: failed to start\n", cpu);
                 return -EIO;
         }
 
         synchronise_count_master(cpu);
+
+        /* Wait for CPU to finish startup & mark itself online before return */
+        wait_for_completion(&cpu_running);
         return 0;
 }