前面聊的

最近在调试项目的亮屏速度，我们希望在按下power键后到亮屏这个时间能达到500MS以内，在Rockchip 3399和3288上面的时间都不能达到要求，因此引发了一系列的调试之路。

计算按下power键到亮屏的时间

Android 唤醒时间统计

刚开始的时候，我只在android阶段统计时间，也能看到时间的差异，但是不是最准确的，我统计的时间日志如下

01-18 09:13:40.992 683 772 D SurfaceControl: Excessive delay in setPowerMode(): 743ms
01-18 09:13:45.304 683 772 D SurfaceControl: Excessive delay in setPowerMode(): 757ms
01-18 09:13:49.559 683 772 D SurfaceControl: Excessive delay in setPowerMode(): 725ms
01-18 09:18:27.461 683 772 D SurfaceControl: Excessive delay in setPowerMode(): 741ms
01-18 09:18:32.766 683 772 D SurfaceControl: Excessive delay in setPowerMode(): 743ms
01-18 09:18:35.861 683 772 D SurfaceControl: Excessive delay in setPowerMode(): 745ms
01-18 09:18:38.345 683 772 D SurfaceControl: Excessive delay in setPowerMode(): 733ms

Kernel从Power到亮屏的时间统计

后来同事中的精英古总在他的代码上加入了从按下Power键到亮屏的时间，直接通过printk打印，代码如下

diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
old mode 100644
new mode 100755
index 17c3b94..2b39662
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -504,6 +504,7 @@ static int panel_simple_enable(struct drm_panel *panel)
    }
    p->enabled = true;
+    printk("%s exit\n", __func__);
    return 0;
 }
diff --git a/drivers/input/keyboard/rk_keys.c b/drivers/input/keyboard/rk_keys.c
old mode 100644
new mode 100755
index fed5ced..537b599
--- a/drivers/input/keyboard/rk_keys.c
+++ b/drivers/input/keyboard/rk_keys.c
@@ -134,6 +134,10 @@ static void keys_timer(unsigned long _data)
        key_dbg(pdata, "%skey[%s]: report event[%d] state[%d]\n",
            button->type == TYPE_ADC ? "adc" : "gpio",
            button->desc, button->code, button->state);
+        if(strcmp(button->desc, "power") == 0)
+        printk("%skey[%s]: report event[%d] state[%d]\n",
+            button->type == TYPE_ADC ? "adc" : "gpio",
+            button->desc, button->code, button->state);
        input_event(input, EV_KEY, button->code, button->state);
        input_sync(input);
    }