X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fserial%2F8250.c;h=f94109cbb46e683a6a6f7d2fee29d7915b21cc93;hb=fabe1510568acd5194f630dbbcf77a34610d7e9e;hp=0b3ec38ae6147e05ac8e02a917e1427adb4c46e8;hpb=8269cc4e2b0ddcdcb9e7f2034c464ef8613737a1;p=linux-2.6-omap-h63xx.git

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 0b3ec38ae61..f94109cbb46 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -129,7 +129,16 @@ struct uart_8250_port {
 	unsigned char		mcr;
 	unsigned char		mcr_mask;	/* mask of user bits */
 	unsigned char		mcr_force;	/* mask of forced bits */
-	unsigned char		lsr_break_flag;
+
+	/*
+	 * Some bits in registers are cleared on a read, so they must
+	 * be saved whenever the register is read but the bits will not
+	 * be immediately processed.
+	 */
+#define LSR_SAVE_FLAGS UART_LSR_BRK_ERROR_BITS
+	unsigned char		lsr_saved_flags;
+#define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA
+	unsigned char		msr_saved_flags;
 
 	/*
 	 * We provide a per-port pm hook.
@@ -1238,6 +1247,7 @@ static void serial8250_start_tx(struct uart_port *port)
 		if (up->bugs & UART_BUG_TXEN) {
 			unsigned char lsr, iir;
 			lsr = serial_in(up, UART_LSR);
+			up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
 			iir = serial_in(up, UART_IIR) & 0x0f;
 			if ((up->port.type == PORT_RM9000) ?
 				(lsr & UART_LSR_THRE &&
@@ -1290,18 +1300,10 @@ receive_chars(struct uart_8250_port *up, unsigned int *status)
 		flag = TTY_NORMAL;
 		up->port.icount.rx++;
 
-#ifdef CONFIG_SERIAL_8250_CONSOLE
-		/*
-		 * Recover the break flag from console xmit
-		 */
-		if (up->port.line == up->port.cons->index) {
-			lsr |= up->lsr_break_flag;
-			up->lsr_break_flag = 0;
-		}
-#endif
+		lsr |= up->lsr_saved_flags;
+		up->lsr_saved_flags = 0;
 
-		if (unlikely(lsr & (UART_LSR_BI | UART_LSR_PE |
-				    UART_LSR_FE | UART_LSR_OE))) {
+		if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
 			/*
 			 * For statistics only
 			 */
@@ -1392,6 +1394,8 @@ static unsigned int check_modem_status(struct uart_8250_port *up)
 {
 	unsigned int status = serial_in(up, UART_MSR);
 
+	status |= up->msr_saved_flags;
+	up->msr_saved_flags = 0;
 	if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
 	    up->port.info != NULL) {
 		if (status & UART_MSR_TERI)
@@ -1591,7 +1595,8 @@ static void serial8250_timeout(unsigned long data)
 static void serial8250_backup_timeout(unsigned long data)
 {
 	struct uart_8250_port *up = (struct uart_8250_port *)data;
-	unsigned int iir, ier = 0;
+	unsigned int iir, ier = 0, lsr;
+	unsigned long flags;
 
 	/*
 	 * Must disable interrupts or else we risk racing with the interrupt
@@ -1610,9 +1615,13 @@ static void serial8250_backup_timeout(unsigned long data)
 	 * the "Diva" UART used on the management processor on many HP
 	 * ia64 and parisc boxes.
 	 */
+	spin_lock_irqsave(&up->port.lock, flags);
+	lsr = serial_in(up, UART_LSR);
+	up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
+	spin_unlock_irqrestore(&up->port.lock, flags);
 	if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) &&
 	    (!uart_circ_empty(&up->port.info->xmit) || up->port.x_char) &&
-	    (serial_in(up, UART_LSR) & UART_LSR_THRE)) {
+	    (lsr & UART_LSR_THRE)) {
 		iir &= ~(UART_IIR_ID | UART_IIR_NO_INT);
 		iir |= UART_IIR_THRI;
 	}
@@ -1631,13 +1640,14 @@ static unsigned int serial8250_tx_empty(struct uart_port *port)
 {
 	struct uart_8250_port *up = (struct uart_8250_port *)port;
 	unsigned long flags;
-	unsigned int ret;
+	unsigned int lsr;
 
 	spin_lock_irqsave(&up->port.lock, flags);
-	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
+	lsr = serial_in(up, UART_LSR);
+	up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
 	spin_unlock_irqrestore(&up->port.lock, flags);
 
-	return ret;
+	return lsr & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
 }
 
 static unsigned int serial8250_get_mctrl(struct uart_port *port)
@@ -1708,8 +1718,7 @@ static inline void wait_for_xmitr(struct uart_8250_port *up, int bits)
 	do {
 		status = serial_in(up, UART_LSR);
 
-		if (status & UART_LSR_BI)
-			up->lsr_break_flag = UART_LSR_BI;
+		up->lsr_saved_flags |= status & LSR_SAVE_FLAGS;
 
 		if (--tmout == 0)
 			break;
@@ -1718,8 +1727,12 @@ static inline void wait_for_xmitr(struct uart_8250_port *up, int bits)
 
 	/* Wait up to 1s for flow control if necessary */
 	if (up->port.flags & UPF_CONS_FLOW) {
-		tmout = 1000000;
-		while (!(serial_in(up, UART_MSR) & UART_MSR_CTS) && --tmout) {
+		unsigned int tmout;
+		for (tmout = 1000000; tmout; tmout--) {
+			unsigned int msr = serial_in(up, UART_MSR);
+			up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
+			if (msr & UART_MSR_CTS)
+				break;
 			udelay(1);
 			touch_nmi_watchdog();
 		}
@@ -1888,6 +1901,18 @@ static int serial8250_startup(struct uart_port *port)
 
 	spin_unlock_irqrestore(&up->port.lock, flags);
 
+	/*
+	 * Clear the interrupt registers again for luck, and clear the
+	 * saved flags to avoid getting false values from polling
+	 * routines or the previous session.
+	 */
+	serial_inp(up, UART_LSR);
+	serial_inp(up, UART_RX);
+	serial_inp(up, UART_IIR);
+	serial_inp(up, UART_MSR);
+	up->lsr_saved_flags = 0;
+	up->msr_saved_flags = 0;
+
 	/*
 	 * Finally, enable interrupts.  Note: Modem status interrupts
 	 * are set via set_termios(), which will be occurring imminently
@@ -1906,14 +1931,6 @@ static int serial8250_startup(struct uart_port *port)
 		(void) inb_p(icp);
 	}
 
-	/*
-	 * And clear the interrupt registers again for luck.
-	 */
-	(void) serial_inp(up, UART_LSR);
-	(void) serial_inp(up, UART_RX);
-	(void) serial_inp(up, UART_IIR);
-	(void) serial_inp(up, UART_MSR);
-
 	return 0;
 }
 
@@ -2484,6 +2501,16 @@ serial8250_console_write(struct console *co, const char *s, unsigned int count)
 	wait_for_xmitr(up, BOTH_EMPTY);
 	serial_out(up, UART_IER, ier);
 
+	/*
+	 *	The receive handling will happen properly because the
+	 *	receive ready bit will still be set; it is not cleared
+	 *	on read.  However, modem control will not, we must
+	 *	call it if we have saved something in the saved flags
+	 *	while processing with interrupts off.
+	 */
+	if (up->msr_saved_flags)
+		check_modem_status(up);
+
 	if (locked)
 		spin_unlock(&up->port.lock);
 	local_irq_restore(flags);
@@ -2514,7 +2541,7 @@ static int __init serial8250_console_setup(struct console *co, char *options)
 	return uart_set_options(port, co, baud, parity, bits, flow);
 }
 
-static int __init serial8250_console_early_setup(void)
+static int serial8250_console_early_setup(void)
 {
 	return serial8250_find_port_for_earlycon();
 }
@@ -2650,8 +2677,9 @@ static int __devinit serial8250_probe(struct platform_device *dev)
 		ret = serial8250_register_port(&port);
 		if (ret < 0) {
 			dev_err(&dev->dev, "unable to register port at index %d "
-				"(IO%lx MEM%lx IRQ%d): %d\n", i,
-				p->iobase, p->mapbase, p->irq, ret);
+				"(IO%lx MEM%llx IRQ%d): %d\n", i,
+				p->iobase, (unsigned long long)p->mapbase,
+				p->irq, ret);
 		}
 	}
 	return 0;