Merge remote-tracking branch 'tmk/master'

[max/tmk_keyboard.git] / tmk_core / protocol / ibmpc.c

diff --git a/tmk_core/protocol/ibmpc.c b/tmk_core/protocol/ibmpc.c
index a071db1986da8e93e827cb5bac7527a6e7f72812..5f2ca79b2fba9f1bd8067b46ed1d2ca8ca6044a1 100644 (file)
--- a/tmk_core/protocol/ibmpc.c
+++ b/tmk_core/protocol/ibmpc.c
@@ -253,8 +253,8 @@ ISR(IBMPC_INT_VECT)
     if (isr_state == 0x8000) {
         timer_start = t;
     } else {
-        // should not take more than 1ms
-        if (timer_start != t && (uint8_t)(timer_start + 1) != t) {
+        // This gives 2.0ms at least before timeout
+        if ((uint8_t)(t - timer_start) >= 3) {
             ibmpc_isr_debug = isr_state;
             ibmpc_error = IBMPC_ERR_TIMEOUT;
             goto ERROR;
@@ -359,12 +359,17 @@ ISR(IBMPC_INT_VECT)
         case 0b01010000:
         case 0b11010000:
             // AT-done
-            // DO NOT check stop bit. Zenith Z-150(AT) asserts stop bit as low for no reason.
-            // https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-AT-Keyboard-Protocol#zenith-z-150-beige
             // TODO: parity check?
             ibmpc_isr_debug = isr_state;
+            // stop bit check
+            if (isr_state & 0x8000) {
+                ibmpc_protocol = IBMPC_PROTOCOL_AT;
+            } else {
+                // Zenith Z-150 AT(beige/white lable) asserts stop bit as low
+                // https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-AT-Keyboard-Protocol#zenith-z-150-beige
+                ibmpc_protocol = IBMPC_PROTOCOL_AT_Z150;
+            }
             isr_state = isr_state>>6;
-            ibmpc_protocol = IBMPC_PROTOCOL_AT;
             goto DONE;
             break;
         case 0b01100000: