diff --git a/ChangeLog b/ChangeLog
index 1469014..02ed6dc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2012-06-08  Niibe Yutaka  <gniibe@fsij.org>
+
+	Emit LED light while computation (or asking user input).
+	* src/usb-icc.c (icc_handle_timeout): Call led_blink.
+	* src/openpgp.c (cmd_pso, cmd_internal_authenticate): Call
+	LED_WAIT_MODE, LED_STATUS_MODE to show "it's under computation".
+	* src/openpgp-do.c (gpg_do_keygen): Ditto.
+	* src/gnuk.h (LED_WAIT_MODE): Rename (was: LED_INPUT_MODE).
+	* src/main.c (display_interaction): Change the behavior of LED,
+	now, it's mostly ON (was: mostly OFF).
+
 2012-06-07  Niibe Yutaka  <gniibe@fsij.org>
 
 	* src/openpgp.c (cmd_internal_authenticate): Add check for input
diff --git a/src/gnuk.h b/src/gnuk.h
index 7b637d8..cebb700 100644
--- a/src/gnuk.h
+++ b/src/gnuk.h
@@ -367,7 +367,7 @@ extern const uint8_t gnukStringSerial[];
 #define LED_ONESHOT_LONG  ((eventmask_t)2)
 #define LED_TWOSHOT       ((eventmask_t)4)
 #define LED_STATUS_MODE   ((eventmask_t)8)
-#define LED_INPUT_MODE   ((eventmask_t)16)
+#define LED_WAIT_MODE    ((eventmask_t)16)
 #define LED_FATAL_MODE   ((eventmask_t)32)
 extern Thread *main_thread;
 extern void led_blink (int spec);
diff --git a/src/main.c b/src/main.c
index 33fe8e8..1ebf12f 100644
--- a/src/main.c
+++ b/src/main.c
@@ -210,14 +210,14 @@ static volatile uint8_t fatal_code;
 
 Thread *main_thread;
 
-#define GNUK_INIT           0
-#define GNUK_RUNNING        1
-#define GNUK_INPUT_WAIT     2
-#define GNUK_FATAL        255
+#define GNUK_INIT	  0
+#define GNUK_RUNNING	  1
+#define GNUK_WAIT	  2
+#define GNUK_FATAL	255
 /*
  * 0 for initializing
  * 1 for normal mode
- * 2 for input waiting
+ * 2 for input waiting / under calculation
  * 255 for fatal
  */
 static uint8_t main_mode;
@@ -226,10 +226,11 @@ static void display_interaction (void)
 {
   eventmask_t m;
 
+  set_led (1);
   while (1)
     {
       m = chEvtWaitOne (ALL_EVENTS);
-      set_led (1);
+      set_led (0);
       switch (m)
 	{
 	case LED_ONESHOT_SHORT:
@@ -239,24 +240,21 @@ static void display_interaction (void)
 	  chThdSleep (MS2ST (400));
 	  break;
 	case LED_TWOSHOT:
-	  chThdSleep (MS2ST (50));
-	  set_led (0);
 	  chThdSleep (MS2ST (50));
 	  set_led (1);
 	  chThdSleep (MS2ST (50));
+	  set_led (0);
+	  chThdSleep (MS2ST (50));
 	  break;
 	case LED_STATUS_MODE:
-	  chThdSleep (MS2ST (400));
-	  set_led (0);
 	  return;
 	case LED_FATAL_MODE:
 	  main_mode = GNUK_FATAL;
-	  set_led (0);
 	  return;
 	default:
 	  break;
 	}
-      set_led (0);
+      set_led (1);
     }
 }
 
@@ -434,11 +432,8 @@ main (int argc, char *argv[])
 	case LED_FATAL_MODE:
 	  main_mode = GNUK_FATAL;
 	  break;
-	case LED_INPUT_MODE:
-	  main_mode = GNUK_INPUT_WAIT;
-	  set_led (1);
-	  chThdSleep (MS2ST (400));
-	  set_led (0);
+	case LED_WAIT_MODE:
+	  main_mode = GNUK_WAIT;
 	  break;
 	default:
 	  break;
@@ -455,7 +450,7 @@ main (int argc, char *argv[])
 	  set_led (0);
 	  chThdSleep (LED_TIMEOUT_STOP * 3);
 	  break;
-	case GNUK_INPUT_WAIT:
+	case GNUK_WAIT:
 	  display_interaction ();
 	  break;
 	case GNUK_RUNNING:
diff --git a/src/openpgp-do.c b/src/openpgp-do.c
index 8f797db..43088f6 100644
--- a/src/openpgp-do.c
+++ b/src/openpgp-do.c
@@ -1506,7 +1506,9 @@ gpg_do_keygen (uint8_t kk_byte)
   else
     keystring_admin = NULL;
 
+  chEvtSignal (main_thread, LED_WAIT_MODE);
   p_q_modulus = rsa_genkey ();
+  chEvtSignal (main_thread, LED_STATUS_MODE);
   if (p_q_modulus == NULL)
     {
       GPG_MEMORY_FAILURE ();
diff --git a/src/openpgp.c b/src/openpgp.c
index a46e95e..9fad156 100644
--- a/src/openpgp.c
+++ b/src/openpgp.c
@@ -118,7 +118,7 @@ get_pinpad_input (int msg_code)
 {
   int r;
 
-  chEvtSignal (main_thread, LED_INPUT_MODE);
+  chEvtSignal (main_thread, LED_WAIT_MODE);
   r = pinpad_getline (msg_code, MS2ST (8000));
   chEvtSignal (main_thread, LED_STATUS_MODE);
   return r;
@@ -701,8 +701,10 @@ cmd_pso (void)
 	  DEBUG_SHORT (len);
 	  DEBUG_BINARY (&kd[GPG_KEY_FOR_SIGNING], KEY_CONTENT_LEN);
 
+	  chEvtSignal (main_thread, LED_WAIT_MODE);
 	  r = rsa_sign (apdu.cmd_apdu_data, res_APDU, len,
 			&kd[GPG_KEY_FOR_SIGNING]);
+	  chEvtSignal (main_thread, LED_STATUS_MODE);
 	  if (r < 0)
 	    {
 	      ac_reset_pso_cds ();
@@ -727,8 +729,10 @@ cmd_pso (void)
 
       /* Skip padding 0x00 */
       len--;
+      chEvtSignal (main_thread, LED_WAIT_MODE);
       r = rsa_decrypt (apdu.cmd_apdu_data+1, res_APDU, len,
 		       &kd[GPG_KEY_FOR_DECRYPTION]);
+      chEvtSignal (main_thread, LED_STATUS_MODE);
       if (r < 0)
 	GPG_ERROR ();
     }
@@ -772,8 +776,10 @@ cmd_internal_authenticate (void)
 	  return;
 	}
 
+      chEvtSignal (main_thread, LED_WAIT_MODE);
       r = rsa_sign (apdu.cmd_apdu_data, res_APDU, len,
 		    &kd[GPG_KEY_FOR_AUTHENTICATION]);
+      chEvtSignal (main_thread, LED_STATUS_MODE);
       if (r < 0)
 	GPG_ERROR ();
     }
diff --git a/src/usb-icc.c b/src/usb-icc.c
index 67b04e5..bb04104 100644
--- a/src/usb-icc.c
+++ b/src/usb-icc.c
@@ -1260,6 +1260,7 @@ icc_handle_timeout (struct ccid *c)
     {
     case ICC_STATE_EXECUTE:
       icc_send_data_block (c, ICC_CMD_STATUS_TIMEEXT);
+      led_blink (2);
       break;
     default:
       break;