--- linux-2.4.20-20.7/drivers/char/serial.c.orig	Mon Aug 18 11:33:18 2003
+++ linux-2.4.20-20.7/drivers/char/serial.c	Wed Nov 12 11:27:31 2003
@@ -797,6 +797,23 @@
 	}
 }
 
+/*
+ * Returns != 0 (true) if UART is ready for more transmit data.
+ * This function contains a work-around for a silicon bug in the UARTs 
+ * of the AMD Elan microcontroller. The LSR THRE bit is set late and 
+ * may be missed by the interrupt routine, so an IIR THRI status is also
+ * treated as an LSR THRE status. This causes xmit data loss on 16C654 
+ * UARTs (and perhaps others) so the work-around is applied only to 
+ * ports detected as generic UART types 8250, 16450, 16550 and 16550A. 
+ */
+static _INLINE_ int uart_transmit_ready(struct async_struct *info,
+					int status, int iir)
+{
+	return (status & UART_LSR_THRE) || 
+	       ((info->state->type <= PORT_16550A) &&
+	        ((iir & UART_IIR_ID) == UART_IIR_THRI));
+}
+
 #ifdef CONFIG_SERIAL_SHARE_IRQ
 /*
  * This is the serial driver's generic interrupt routine
@@ -919,9 +936,7 @@
 		if (status & UART_LSR_DR)
 			receive_chars(info, &status, regs);
 		check_modem_status(info);
-		if ((status & UART_LSR_THRE) ||
-		    /* For buggy ELAN processors */
-		    ((iir & UART_IIR_ID) == UART_IIR_THRI))
+		if (uart_transmit_ready(info, status, iir))
 			transmit_chars(info, 0);
 		if (pass_counter++ > RS_ISR_PASS_LIMIT) {
 #if SERIAL_DEBUG_INTR