X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fserial%2F8250.c;h=27f34a9f9cb750297ea6527ce5d181b47b0ca660;hb=d26acd92fa990764b72608a68224f46fac377032;hp=be95e55b228b83077ace9af42764d75f8a286d11;hpb=6c118e43dc513a7118b49b9ff953fe61e14515dc;p=linux-2.6

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index be95e55b22..9ccc563d87 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -12,8 +12,6 @@
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
- *  $Id: 8250.c,v 1.90 2002/07/28 10:03:27 rmk Exp $
- *
  * A note about mapbase / membase
  *
  *  mapbase is the physical address of the IO port.
@@ -1289,13 +1287,24 @@ static void serial8250_enable_ms(struct uart_port *port)
 static void
 receive_chars(struct uart_8250_port *up, unsigned int *status)
 {
-	struct tty_struct *tty = up->port.info->tty;
+	struct tty_struct *tty = up->port.info->port.tty;
 	unsigned char ch, lsr = *status;
 	int max_count = 256;
 	char flag;
 
 	do {
-		ch = serial_inp(up, UART_RX);
+		if (likely(lsr & UART_LSR_DR))
+			ch = serial_inp(up, UART_RX);
+		else
+			/*
+			 * Intel 82571 has a Serial Over Lan device that will
+			 * set UART_LSR_BI without setting UART_LSR_DR when
+			 * it receives a break. To avoid reading from the
+			 * receive buffer without UART_LSR_DR bit set, we
+			 * just force the read character to be 0
+			 */
+			ch = 0;
+
 		flag = TTY_NORMAL;
 		up->port.icount.rx++;
 
@@ -1344,7 +1353,7 @@ receive_chars(struct uart_8250_port *up, unsigned int *status)
 
 ignore_char:
 		lsr = serial_inp(up, UART_LSR);
-	} while ((lsr & UART_LSR_DR) && (max_count-- > 0));
+	} while ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (max_count-- > 0));
 	spin_unlock(&up->port.lock);
 	tty_flip_buffer_push(tty);
 	spin_lock(&up->port.lock);
@@ -1427,7 +1436,7 @@ serial8250_handle_port(struct uart_8250_port *up)
 
 	DEBUG_INTR("status = %x...", status);
 
-	if (status & UART_LSR_DR)
+	if (status & (UART_LSR_DR | UART_LSR_BI))
 		receive_chars(up, &status);
 	check_modem_status(up);
 	if (status & UART_LSR_THRE)
@@ -1877,6 +1886,8 @@ static int serial8250_startup(struct uart_port *port)
 		 * allow register changes to become visible.
 		 */
 		spin_lock_irqsave(&up->port.lock, flags);
+		if (up->port.flags & UPF_SHARE_IRQ)
+			disable_irq_nosync(up->port.irq);
 
 		wait_for_xmitr(up, UART_LSR_THRE);
 		serial_out_sync(up, UART_IER, UART_IER_THRI);
@@ -1888,6 +1899,8 @@ static int serial8250_startup(struct uart_port *port)
 		iir = serial_in(up, UART_IIR);
 		serial_out(up, UART_IER, 0);
 
+		if (up->port.flags & UPF_SHARE_IRQ)
+			enable_irq(up->port.irq);
 		spin_unlock_irqrestore(&up->port.lock, flags);
 
 		/*
@@ -1895,14 +1908,22 @@ static int serial8250_startup(struct uart_port *port)
 		 * kick the UART on a regular basis.
 		 */
 		if (!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) {
+			up->bugs |= UART_BUG_THRE;
 			pr_debug("ttyS%d - using backup timer\n", port->line);
-			up->timer.function = serial8250_backup_timeout;
-			up->timer.data = (unsigned long)up;
-			mod_timer(&up->timer, jiffies +
-				poll_timeout(up->port.timeout) + HZ / 5);
 		}
 	}
 
+	/*
+	 * The above check will only give an accurate result the first time
+	 * the port is opened so this value needs to be preserved.
+	 */
+	if (up->bugs & UART_BUG_THRE) {
+		up->timer.function = serial8250_backup_timeout;
+		up->timer.data = (unsigned long)up;
+		mod_timer(&up->timer, jiffies +
+			  poll_timeout(up->port.timeout) + HZ / 5);
+	}
+
 	/*
 	 * If the "interrupt" for this port doesn't correspond with any
 	 * hardware interrupt, we use a timer-based system.  The original
@@ -2934,7 +2955,7 @@ static int __init serial8250_init(void)
 	if (nr_uarts > UART_NR)
 		nr_uarts = UART_NR;
 
-	printk(KERN_INFO "Serial: 8250/16550 driver $Revision: 1.90 $ "
+	printk(KERN_INFO "Serial: 8250/16550 driver"
 		"%d ports, IRQ sharing %sabled\n", nr_uarts,
 		share_irqs ? "en" : "dis");
 
@@ -2995,7 +3016,7 @@ EXPORT_SYMBOL(serial8250_suspend_port);
 EXPORT_SYMBOL(serial8250_resume_port);
 
 MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("Generic 8250/16x50 serial driver $Revision: 1.90 $");
+MODULE_DESCRIPTION("Generic 8250/16x50 serial driver");
 
 module_param(share_irqs, uint, 0644);
 MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices"