2 files changed, 18 insertions, 4 deletions

diff --git a/drivers/input/serio/libps2.c b/drivers/input/serio/libps2.c
index 2b304c22c200..67248c31e19a 100644
--- a/drivers/input/serio/libps2.c
+++ b/drivers/input/serio/libps2.c
@@ -262,9 +262,17 @@ int ps2_handle_ack(struct ps2dev *ps2dev, unsigned char data)
                         break;
 
                 case PS2_RET_NAK:
-                        ps2dev->nak = 1;
+                        ps2dev->flags |= PS2_FLAG_NAK;
+                        ps2dev->nak = PS2_RET_NAK;
                         break;
 
+                case PS2_RET_ERR:
+                        if (ps2dev->flags & PS2_FLAG_NAK) {
+                                ps2dev->flags &= ~PS2_FLAG_NAK;
+                                ps2dev->nak = PS2_RET_ERR;
+                                break;
+                        }
+
                 /*
                  * Workaround for mice which don't ACK the Get ID command.
                  * These are valid mouse IDs that we recognize.
@@ -282,8 +290,11 @@ int ps2_handle_ack(struct ps2dev *ps2dev, unsigned char data)
         }
 
 
-        if (!ps2dev->nak && ps2dev->cmdcnt)
-                ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1;
+        if (!ps2dev->nak) {
+                ps2dev->flags &= ~PS2_FLAG_NAK;
+                if (ps2dev->cmdcnt)
+                        ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1;
+        }
 
         ps2dev->flags &= ~PS2_FLAG_ACK;
         wake_up(&ps2dev->wait);
@@ -329,6 +340,7 @@ void ps2_cmd_aborted(struct ps2dev *ps2dev)
         if (ps2dev->flags & (PS2_FLAG_ACK | PS2_FLAG_CMD))
                 wake_up(&ps2dev->wait);
 
-        ps2dev->flags = 0;
+        /* reset all flags except last nack */
+        ps2dev->flags &= PS2_FLAG_NAK;
 }
 EXPORT_SYMBOL(ps2_cmd_aborted);
diff --git a/include/linux/libps2.h b/include/linux/libps2.h
index afc413369101..b94534b7e266 100644
--- a/include/linux/libps2.h
+++ b/include/linux/libps2.h
@@ -18,11 +18,13 @@
 #define PS2_RET_ID              0x00
 #define PS2_RET_ACK             0xfa
 #define PS2_RET_NAK             0xfe
+#define PS2_RET_ERR             0xfc
 
 #define PS2_FLAG_ACK            1       /* Waiting for ACK/NAK */
 #define PS2_FLAG_CMD            2       /* Waiting for command to finish */
 #define PS2_FLAG_CMD1           4       /* Waiting for the first byte of command response */
 #define PS2_FLAG_WAITID         8       /* Command execiting is GET ID */
+#define PS2_FLAG_NAK            16      /* Last transmission was NAKed */
 
 struct ps2dev {
         struct serio *serio;