The following patch adds the "resend" capability to the keyboard driver;

when the host driver detects a parity or framing error, we can ask the
keyboard to resend the data, instead of treating random garbage as
valid data.
We also export serio_interrupt() - serio modules are using it, yet you
can't use them as modules without this symbol exported.
  -- Russell King

drivers/input/keyboard/atkbd.c

@@ -98,6 +98,7 @@ static unsigned char atkbd_set3_keycode[512] = {
 #define ATKBD_CMD_ENABLE	0x00f4
 #define ATKBD_CMD_RESET_DIS	0x00f5
 #define ATKBD_CMD_SETALL_MB	0x00f8
+#define ATKBD_CMD_RESEND	0x00fe
 #define ATKBD_CMD_EX_ENABLE	0x10ea
 #define ATKBD_CMD_EX_SETLEDS	0x20eb
 
@@ -141,9 +142,16 @@ static void atkbd_interrupt(struct serio *serio, unsigned char data, unsigned in
 	int code = data;
 
 #ifdef ATKBD_DEBUG
-	printk(KERN_DEBUG "atkbd.c: Received %02x\n", data);
+	printk(KERN_DEBUG "atkbd.c: Received %02x flags %02x\n", data, flags);
 #endif
 
+	/* Interface error.  Request that the keyboard resend. */
+	if (flags & (SERIO_FRAME | SERIO_PARITY)) {
+		printk("atkbd.c: frame/parity error: %02x\n", flags);
+		serio_write(serio, ATKBD_CMD_RESEND);
+		return;
+	}
+
 	switch (code) {
 		case ATKBD_RET_ACK:
 			atkbd->ack = 1;

drivers/input/serio/serio.c

@@ -42,6 +42,7 @@ MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
 MODULE_DESCRIPTION("Serio abstraction core");
 MODULE_LICENSE("GPL");
 
+EXPORT_SYMBOL(serio_interrupt);
 EXPORT_SYMBOL(serio_register_port);
 EXPORT_SYMBOL(serio_unregister_port);
 EXPORT_SYMBOL(serio_register_device);

include/linux/serio.h

@@ -94,8 +94,12 @@ static __inline__ void serio_dev_write_wakeup(struct serio *serio)
 		serio->dev->write_wakeup(serio);
 }
 
+/*
+ * bit masks for use in "interrupt" flags (3rd argument)
+ */
 #define SERIO_TIMEOUT	1
 #define SERIO_PARITY	2
+#define SERIO_FRAME	4
 
 #define SERIO_TYPE	0xff000000UL
 #define SERIO_XT	0x00000000UL