ddr_rk32.c: optimize timeout procedure when change freq

Signed-off-by: cl <cl@rock-chips.com>

diff --git a/arch/arm/mach-rockchip/ddr_rk32.c b/arch/arm/mach-rockchip/ddr_rk32.c
index 4ce3220f7df0c1a20570c948e719003b885a584d..d9e996c99be135d00424b7bf0de806c9bd2f7f31 100755 (executable)
--- a/arch/arm/mach-rockchip/ddr_rk32.c
+++ b/arch/arm/mach-rockchip/ddr_rk32.c
@@ -3832,8 +3832,6 @@ static inline void set_cpuX_paused(unsigned int cpu, bool pause) { DATA(cpu_paus
 static inline bool is_cpuX_paused(unsigned int cpu) { smp_rmb(); return DATA(p_cpu_pause)[cpu]; }
 static inline void set_cpu0_paused(bool pause) { DATA(p_cpu_pause)[0] = pause; smp_wmb();}
 
-#define MAX_TIMEOUT (16000000UL << 6) //>0.64s
-
 /* Do not use stack, safe on SMP */
 void PIE_FUNC(_pause_cpu)(void *arg)
 {       
@@ -3859,35 +3857,39 @@ static void wait_cpu(void *info)
 
 static int call_with_single_cpu(u32 (*fn)(void *arg), void *arg)
 {
-    u32 timeout = MAX_TIMEOUT;
-    unsigned int cpu;
-    unsigned int this_cpu = smp_processor_id();
-    int ret = 0;
-
-    cpu_maps_update_begin();
-    local_bh_disable();
-    set_cpu0_paused(true);
-    smp_call_function((smp_call_func_t)pause_cpu, NULL, 0);
-
-    for_each_online_cpu(cpu) {
-        if (cpu == this_cpu)
-            continue;
-        while (!is_cpuX_paused(cpu) && --timeout);
-        if (timeout == 0) {
-            pr_err("pause cpu %d timeout\n", cpu);
-            goto out;
-        }
-    }
-
-    ret = fn(arg);
-
+       s64 now_ns, timeout_ns;
+       unsigned int cpu;
+       unsigned int this_cpu = smp_processor_id();
+       int ret = 0;
+
+       cpu_maps_update_begin();
+       local_bh_disable();
+
+       /* It should take much less than 1s to pause the cpus. It typically
+       * takes around 20us. */
+       timeout_ns = ktime_to_ns(ktime_add_ns(ktime_get(), NSEC_PER_SEC));
+       now_ns = ktime_to_ns(ktime_get());
+       set_cpu0_paused(true);
+       smp_call_function((smp_call_func_t)pause_cpu, NULL, 0);
+       for_each_online_cpu(cpu) {
+               if (cpu == this_cpu)
+                       continue;
+               while (!is_cpuX_paused(cpu) && (now_ns < timeout_ns))
+                       now_ns = ktime_to_ns(ktime_get());
+               if (now_ns >= timeout_ns) {
+                       pr_err("pause cpu %d timeout\n", cpu);
+                       ret = -EPERM;
+                       goto out;
+               }
+       }
+       ret = fn(arg);
 out:
-    set_cpu0_paused(false);
-    local_bh_enable();
-    smp_call_function(wait_cpu, NULL, true);
-    cpu_maps_update_done();
+       set_cpu0_paused(false);
+       local_bh_enable();
+       smp_call_function(wait_cpu, NULL, true);
+       cpu_maps_update_done();
 
-    return ret;
+       return ret;
 }
 
 void PIE_FUNC(ddr_adjust_config)(void *arg)