openwrt/target/linux/pxa/patches-2.6.21/024-bugfix-serial-register-status.patch

Index: linux-2.6.21.7/drivers/serial/pxa.c
===================================================================
--- linux-2.6.21.7.orig/drivers/serial/pxa.c
+++ linux-2.6.21.7/drivers/serial/pxa.c
@@ -57,6 +57,8 @@ struct uart_pxa_port {
 	unsigned int            lsr_break_flag;
 	unsigned int		cken;
 	char			*name;
+	unsigned int		msr;
+	unsigned int		lsr;
 };
 
 static inline unsigned int serial_in(struct uart_pxa_port *up, int offset)
@@ -159,6 +161,7 @@ static inline void receive_chars(struct 
 
 	ignore_char:
 		*status = serial_in(up, UART_LSR);
+		up->lsr = *status;
 	} while ((*status & UART_LSR_DR) && (max_count-- > 0));
 	tty_flip_buffer_push(tty);
 }
@@ -211,7 +214,7 @@ static inline void check_modem_status(st
 	int status;
 
 	status = serial_in(up, UART_MSR);
-
+	up->msr = status;
 	if ((status & UART_MSR_ANY_DELTA) == 0)
 		return;
 
@@ -242,6 +245,7 @@ static inline irqreturn_t serial_pxa_irq
 		//printk(KERN_WARNING "serial_pxa_irq: odd -- interrupt triggered, but no interrupt in IIR: %08x\n",iir);
 	}
 	lsr = serial_in(up, UART_LSR);
+	up->lsr = lsr;
 	if (lsr & UART_LSR_DR)
 		receive_chars(up, &lsr);
 	check_modem_status(up);
@@ -258,7 +262,7 @@ static unsigned int serial_pxa_tx_empty(
 	unsigned int ret;
 
 	spin_lock_irqsave(&up->port.lock, flags);
-	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
+	ret = up->lsr & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
 	spin_unlock_irqrestore(&up->port.lock, flags);
 
 	return ret;
@@ -270,7 +274,7 @@ static unsigned int serial_pxa_get_mctrl
 	unsigned char status;
 	unsigned int ret;
 
-	status = serial_in(up, UART_MSR);
+	status = up->msr;
 
 	ret = 0;
 	if (status & UART_MSR_DCD)
@@ -400,10 +404,10 @@ static int serial_pxa_startup(struct uar
 	/*
 	 * And clear the interrupt registers again for luck.
 	 */
-	(void) serial_in(up, UART_LSR);
+	up->lsr = serial_in(up, UART_LSR);
 	(void) serial_in(up, UART_RX);
 	(void) serial_in(up, UART_IIR);
-	(void) serial_in(up, UART_MSR);
+	up->msr = serial_in(up, UART_MSR);
 
 	return 0;
 }