a68555f48d
The previous code does a full flush of the uart after every character. Unfortunately, this can cause transmission delays on some serial ports. This patch changes the code so that it does a flush at the end of every printk instead of at the end of every character. This reduces the time it takes to transmit serial messages (up to 9% on my Asrock e350m1 board). It also makes the transmission time more consistent which is important when performing timing tests via serial transmissions. Change-Id: I6b28488b905da68c6d68d7c517cc743cde567d70 Signed-off-by: Kevin O'Connor <kevin@koconnor.net> Reviewed-on: http://review.coreboot.org/90 Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org> Tested-by: build bot (Jenkins) Reviewed-by: Rudolf Marek <r.marek@assembler.cz> Reviewed-by: Sven Schnelle <svens@stackframe.org>
56 lines
1.4 KiB
C
56 lines
1.4 KiB
C
/*
|
|
* This file is part of the coreboot project.
|
|
*
|
|
* Copyright (C) 2003 Eric Biederman
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; version 2 of the License.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#include <console/console.h>
|
|
#include <uart8250.h>
|
|
#include <pc80/mc146818rtc.h>
|
|
|
|
static void ttyS0_init(void)
|
|
{
|
|
uart_init();
|
|
}
|
|
|
|
static void ttyS0_tx_byte(unsigned char data)
|
|
{
|
|
uart8250_tx_byte(CONFIG_TTYS0_BASE, data);
|
|
}
|
|
|
|
static void ttyS0_tx_flush(void)
|
|
{
|
|
uart8250_tx_flush(CONFIG_TTYS0_BASE);
|
|
}
|
|
|
|
static unsigned char ttyS0_rx_byte(void)
|
|
{
|
|
return uart8250_rx_byte(CONFIG_TTYS0_BASE);
|
|
}
|
|
|
|
static int ttyS0_tst_byte(void)
|
|
{
|
|
return uart8250_can_rx_byte(CONFIG_TTYS0_BASE);
|
|
}
|
|
|
|
static const struct console_driver uart8250_console __console = {
|
|
.init = ttyS0_init,
|
|
.tx_byte = ttyS0_tx_byte,
|
|
.tx_flush = ttyS0_tx_flush,
|
|
.rx_byte = ttyS0_rx_byte,
|
|
.tst_byte = ttyS0_tst_byte,
|
|
};
|