From 0c80bfca714e953f2575c35e21c0549b679b3d56 Mon Sep 17 00:00:00 2001
From: tmk <hasu@tmk-kbd.com>
Date: Sun, 1 Mar 2020 23:23:55 +0900
Subject: [PATCH] ibmpc_usb: Error recovery with invalid scan code

---
 converter/ibmpc_usb/ibmpc_usb.c | 35 ++++++++++++++++++++++-----------
 1 file changed, 23 insertions(+), 12 deletions(-)

diff --git a/converter/ibmpc_usb/ibmpc_usb.c b/converter/ibmpc_usb/ibmpc_usb.c
index 7e735866..09987535 100644
--- a/converter/ibmpc_usb/ibmpc_usb.c
+++ b/converter/ibmpc_usb/ibmpc_usb.c
@@ -222,8 +222,6 @@ uint8_t matrix_scan(void)
                 ibmpc_error = IBMPC_ERR_NONE;
             }
 
-            xprintf("ID:%04X\n", keyboard_id);
-
             if (0xAB00 == (keyboard_id & 0xFF00)) {         // CodeSet2 PS/2
                 keyboard_kind = PC_AT;
             } else if (0xBF00 == (keyboard_id & 0xFF00)) {  // CodeSet3 Terminal
@@ -241,6 +239,8 @@ uint8_t matrix_scan(void)
                 keyboard_kind = PC_AT;
             }
 
+            xprintf("ID:%04X(%d)\n", keyboard_id, keyboard_kind);
+
             state = SETUP;
             break;
         case SETUP:
@@ -434,6 +434,11 @@ static int8_t process_cs1(void)
     switch (state) {
         case INIT:
             switch (code) {
+                case 0x00:
+                case 0xFF:  // Error/Overrun [3]p.26
+                    xprintf("!CS1_%02X!\n", code);
+                    return -1;
+                    break;
                 case 0xE0:
                     state = E0;
                     break;
@@ -651,6 +656,13 @@ static int8_t process_cs2(void)
     switch (state) {
         case INIT:
             switch (code) {
+                case 0x00:  // Error/Overrun [3]p.26
+                case 0xFF:
+                    matrix_clear();
+                    xprintf("!CS2_%02X!\n", code);
+                    state = INIT;
+                    return -1;
+                    break;
                 case 0xE0:
                     state = E0;
                     break;
@@ -668,11 +680,6 @@ static int8_t process_cs2(void)
                     matrix_make(0x6F);
                     state = INIT;
                     break;
-                case 0x00:  // Overrun [3]p.26
-                    matrix_clear();
-                    xprintf("!CS2_OVERRUN!\n");
-                    state = INIT;
-                    break;
                 case 0xAA:  // Self-test passed
                 case 0xFC:  // Self-test failed
                     // reset or plugin-in new keyboard
@@ -680,13 +687,14 @@ static int8_t process_cs2(void)
                     return -1;
                     break;
                 default:    // normal key make
+                    state = INIT;
                     if (code < 0x80) {
                         matrix_make(code);
                     } else {
                         matrix_clear();
                         xprintf("!CS2_INIT!\n");
+                        return -1;
                     }
-                    state = INIT;
             }
             break;
         case E0:    // E0-Prefixed
@@ -699,13 +707,14 @@ static int8_t process_cs2(void)
                     state = E0_F0;
                     break;
                 default:
+                    state = INIT;
                     if (code < 0x80) {
                         matrix_make(cs2_e0code(code));
                     } else {
                         matrix_clear();
                         xprintf("!CS2_E0!\n");
+                        return -1;
                     }
-                    state = INIT;
             }
             break;
         case F0:    // Break code
@@ -719,13 +728,14 @@ static int8_t process_cs2(void)
                     state = INIT;
                     break;
                 default:
+                    state = INIT;
                     if (code < 0x80) {
                         matrix_break(code);
                     } else {
                         matrix_clear();
                         xprintf("!CS2_F0!\n");
+                        return -1;
                     }
-                    state = INIT;
             }
             break;
         case E0_F0: // Break code of E0-prefixed
@@ -735,13 +745,14 @@ static int8_t process_cs2(void)
                     state = INIT;
                     break;
                 default:
+                    state = INIT;
                     if (code < 0x80) {
                         matrix_break(cs2_e0code(code));
                     } else {
                         matrix_clear();
                         xprintf("!CS2_E0_F0!\n");
+                        return -1;
                     }
-                    state = INIT;
             }
             break;
         // Pause make: E1 14 77
@@ -824,7 +835,7 @@ static int8_t process_cs3(void)
     switch (state) {
         case READY:
             switch (code) {
-                case 0x00:
+                case 0x00:  // Error/Overrun [3]p.26
                 case 0xFF:
                     xprintf("!CS3_%02X!\n", code);
                     return -1;
-- 
2.46.2