linux-kernel - [PATCH 2/2] altera_uart: Simplify altera_uart_console

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Message-Id: <1274799608-4200-1-git-send-email-tklauser@distanz.ch>
Date:	Tue, 25 May 2010 17:00:08 +0200
From:	Tobias Klauser <tklauser@...tanz.ch>
To:	gregkh@...e.de, linux-kernel@...r.kernel.org
Cc:	akpm@...ux-foundation.org, Tobias Klauser <tklauser@...tanz.ch>,
	Thomas Chou <thomas@...ron.com.tw>
Subject: [PATCH 2/2] altera_uart: Simplify altera_uart_console_putc

The check for the TRDY flag after writing the character is not needed.
Also do a cpu_relax() inside the loop.

Pass a struct uart_port to altera_uart_console_putc, so we do not need
to get it (and dereference pointers) for every character.

Cc: Thomas Chou <thomas@...ron.com.tw>
Signed-off-by: Tobias Klauser <tklauser@...tanz.ch>
---
 drivers/serial/altera_uart.c |   23 ++++++++---------------
 1 files changed, 8 insertions(+), 15 deletions(-)

diff --git a/drivers/serial/altera_uart.c b/drivers/serial/altera_uart.c
index b1609cc..7d6afc9 100644
--- a/drivers/serial/altera_uart.c
+++ b/drivers/serial/altera_uart.c
@@ -391,31 +391,24 @@ int __init early_altera_uart_setup(struct altera_uart_platform_uart *platp)
 	return 0;
 }
 
-static void altera_uart_console_putc(struct console *co, const char c)
+static void altera_uart_console_putc(struct uart_port *port, const char c)
 {
-	struct uart_port *port = &(altera_uart_ports + co->index)->port;
-	int i;
+	while (!(readl(port->membase + ALTERA_UART_STATUS_REG) &
+	         ALTERA_UART_STATUS_TRDY_MSK))
+		cpu_relax();
 
-	for (i = 0; i < 0x10000; i++) {
-		if (readl(port->membase + ALTERA_UART_STATUS_REG) &
-		    ALTERA_UART_STATUS_TRDY_MSK)
-			break;
-	}
 	writel(c, port->membase + ALTERA_UART_TXDATA_REG);
-	for (i = 0; i < 0x10000; i++) {
-		if (readl(port->membase + ALTERA_UART_STATUS_REG) &
-		    ALTERA_UART_STATUS_TRDY_MSK)
-			break;
-	}
 }
 
 static void altera_uart_console_write(struct console *co, const char *s,
 				      unsigned int count)
 {
+	struct uart_port *port = &(altera_uart_ports + co->index)->port;
+
 	for (; count; count--, s++) {
-		altera_uart_console_putc(co, *s);
+		altera_uart_console_putc(port, *s);
 		if (*s == '\n')
-			altera_uart_console_putc(co, '\r');
+			altera_uart_console_putc(port, '\r');
 	}
 }
 
-- 
1.6.3.3

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