From: Sascha Hauer <sascha@saschahauer.de>
Date: Thu, 17 Apr 2008 07:39:22 +0000 (+0100)
Subject: [ARM] 4994/1: <IMX UART>: Move error handling into execution path
X-Git-Tag: v2.6.26-rc1~1131^2~2^7~4
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=864eeed051b527c8081e2f85b51ba24823acaf71;p=linux-2.6

[ARM] 4994/1: <IMX UART>: Move error handling into execution path

Move the error handling code for erroneous receive characters into
execution path. This makes the code more readable and the compiler
should know how to optimize this, right?

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---

diff --git a/drivers/serial/imx.c b/drivers/serial/imx.c
index 06fa54c53f..c637ae2191 100644
--- a/drivers/serial/imx.c
+++ b/drivers/serial/imx.c
@@ -354,66 +354,58 @@ static irqreturn_t imx_rxint(int irq, void *dev_id)
 	struct tty_struct *tty = sport->port.info->tty;
 	unsigned long flags, temp;
 
-	rx = readl(sport->port.membase + URXD0);
 	spin_lock_irqsave(&sport->port.lock,flags);
 
-	do {
+	while ((rx = readl(sport->port.membase + URXD0)) & URXD_CHARRDY) {
 		flg = TTY_NORMAL;
 		sport->port.icount.rx++;
 
 		temp = readl(sport->port.membase + USR2);
-		if( temp & USR2_BRCD ) {
+		if (temp & USR2_BRCD) {
 			writel(temp | USR2_BRCD, sport->port.membase + USR2);
-			if(uart_handle_break(&sport->port))
-				goto ignore_char;
+			if (uart_handle_break(&sport->port))
+				continue;
 		}
 
 		if (uart_handle_sysrq_char
 		            (&sport->port, (unsigned char)rx))
-			goto ignore_char;
+			continue;
+
+		if (rx & (URXD_PRERR | URXD_OVRRUN | URXD_FRMERR) ) {
+			if (rx & URXD_PRERR)
+				sport->port.icount.parity++;
+			else if (rx & URXD_FRMERR)
+				sport->port.icount.frame++;
+			if (rx & URXD_OVRRUN)
+				sport->port.icount.overrun++;
+
+			if (rx & sport->port.ignore_status_mask) {
+				if (++ignored > 100)
+					goto out;
+				continue;
+			}
+
+			rx &= sport->port.read_status_mask;
+
+			if (rx & URXD_PRERR)
+				flg = TTY_PARITY;
+			else if (rx & URXD_FRMERR)
+				flg = TTY_FRAME;
+			if (rx & URXD_OVRRUN)
+				flg = TTY_OVERRUN;
 
-		if( rx & (URXD_PRERR | URXD_OVRRUN | URXD_FRMERR) )
-			goto handle_error;
+#ifdef SUPPORT_SYSRQ
+			sport->port.sysrq = 0;
+#endif
+		}
 
-	error_return:
 		tty_insert_flip_char(tty, rx, flg);
-
-	ignore_char:
-		rx = readl(sport->port.membase + URXD0);
-	} while(rx & URXD_CHARRDY);
+	}
 
 out:
 	spin_unlock_irqrestore(&sport->port.lock,flags);
 	tty_flip_buffer_push(tty);
 	return IRQ_HANDLED;
-
-handle_error:
-	if (rx & URXD_PRERR)
-		sport->port.icount.parity++;
-	else if (rx & URXD_FRMERR)
-		sport->port.icount.frame++;
-	if (rx & URXD_OVRRUN)
-		sport->port.icount.overrun++;
-
-	if (rx & sport->port.ignore_status_mask) {
-		if (++ignored > 100)
-			goto out;
-		goto ignore_char;
-	}
-
-	rx &= sport->port.read_status_mask;
-
-	if (rx & URXD_PRERR)
-		flg = TTY_PARITY;
-	else if (rx & URXD_FRMERR)
-		flg = TTY_FRAME;
-	if (rx & URXD_OVRRUN)
-		flg = TTY_OVERRUN;
-
-#ifdef SUPPORT_SYSRQ
-	sport->port.sysrq = 0;
-#endif
-	goto error_return;
 }
 
 /*