synclink_gt fix missed serial input signal changes

Fix missed serial input signal changes caused by rereading the serial
status register during interrupt processing.  Now processing is performed
on original status register value.

Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/synclink_gt.c

@@ -2039,37 +2039,41 @@ static void bh_transmit(struct slgt_info *info)
 		tty_wakeup(tty);
 }
 
-static void dsr_change(struct slgt_info *info)
+static void dsr_change(struct slgt_info *info, unsigned short status)
 {
-	get_signals(info);
+	if (status & BIT3) {
+		info->signals |= SerialSignal_DSR;
+		info->input_signal_events.dsr_up++;
+	} else {
+		info->signals &= ~SerialSignal_DSR;
+		info->input_signal_events.dsr_down++;
+	}
 	DBGISR(("dsr_change %s signals=%04X\n", info->device_name, info->signals));
 	if ((info->dsr_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
 		slgt_irq_off(info, IRQ_DSR);
 		return;
 	}
 	info->icount.dsr++;
-	if (info->signals & SerialSignal_DSR)
-		info->input_signal_events.dsr_up++;
-	else
-		info->input_signal_events.dsr_down++;
 	wake_up_interruptible(&info->status_event_wait_q);
 	wake_up_interruptible(&info->event_wait_q);
 	info->pending_bh |= BH_STATUS;
 }
 
-static void cts_change(struct slgt_info *info)
+static void cts_change(struct slgt_info *info, unsigned short status)
 {
-	get_signals(info);
+	if (status & BIT2) {
+		info->signals |= SerialSignal_CTS;
+		info->input_signal_events.cts_up++;
+	} else {
+		info->signals &= ~SerialSignal_CTS;
+		info->input_signal_events.cts_down++;
+	}
 	DBGISR(("cts_change %s signals=%04X\n", info->device_name, info->signals));
 	if ((info->cts_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
 		slgt_irq_off(info, IRQ_CTS);
 		return;
 	}
 	info->icount.cts++;
-	if (info->signals & SerialSignal_CTS)
-		info->input_signal_events.cts_up++;
-	else
-		info->input_signal_events.cts_down++;
 	wake_up_interruptible(&info->status_event_wait_q);
 	wake_up_interruptible(&info->event_wait_q);
 	info->pending_bh |= BH_STATUS;
@@ -2090,20 +2094,21 @@ static void cts_change(struct slgt_info *info)
 	}
 }
 
-static void dcd_change(struct slgt_info *info)
+static void dcd_change(struct slgt_info *info, unsigned short status)
 {
-	get_signals(info);
+	if (status & BIT1) {
+		info->signals |= SerialSignal_DCD;
+		info->input_signal_events.dcd_up++;
+	} else {
+		info->signals &= ~SerialSignal_DCD;
+		info->input_signal_events.dcd_down++;
+	}
 	DBGISR(("dcd_change %s signals=%04X\n", info->device_name, info->signals));
 	if ((info->dcd_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
 		slgt_irq_off(info, IRQ_DCD);
 		return;
 	}
 	info->icount.dcd++;
-	if (info->signals & SerialSignal_DCD) {
-		info->input_signal_events.dcd_up++;
-	} else {
-		info->input_signal_events.dcd_down++;
-	}
 #if SYNCLINK_GENERIC_HDLC
 	if (info->netcount) {
 		if (info->signals & SerialSignal_DCD)
@@ -2126,20 +2131,21 @@ static void dcd_change(struct slgt_info *info)
 	}
 }
 
-static void ri_change(struct slgt_info *info)
+static void ri_change(struct slgt_info *info, unsigned short status)
 {
-	get_signals(info);
+	if (status & BIT0) {
+		info->signals |= SerialSignal_RI;
+		info->input_signal_events.ri_up++;
+	} else {
+		info->signals &= ~SerialSignal_RI;
+		info->input_signal_events.ri_down++;
+	}
 	DBGISR(("ri_change %s signals=%04X\n", info->device_name, info->signals));
 	if ((info->ri_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
 		slgt_irq_off(info, IRQ_RI);
 		return;
 	}
-	info->icount.dcd++;
-	if (info->signals & SerialSignal_RI) {
-		info->input_signal_events.ri_up++;
-	} else {
-		info->input_signal_events.ri_down++;
-	}
+	info->icount.rng++;
 	wake_up_interruptible(&info->status_event_wait_q);
 	wake_up_interruptible(&info->event_wait_q);
 	info->pending_bh |= BH_STATUS;
@@ -2190,13 +2196,13 @@ static void isr_serial(struct slgt_info *info)
 	}
 
 	if (status & IRQ_DSR)
-		dsr_change(info);
+		dsr_change(info, status);
 	if (status & IRQ_CTS)
-		cts_change(info);
+		cts_change(info, status);
 	if (status & IRQ_DCD)
-		dcd_change(info);
+		dcd_change(info, status);
 	if (status & IRQ_RI)
-		ri_change(info);
+		ri_change(info, status);
 }
 
 static void isr_rdma(struct slgt_info *info)