Prev: cfq-iosched: don't allow aliased requests to starve others
Next: Removing dead {AR,WAVE}LAN
From: tip-bot for Yinghai Lu on 14 Jul 2010 15:20
Commit-ID: 70b0d22d581a5deef7b2876b0c3774635b8d846c
Gitweb: http://git.kernel.org/tip/70b0d22d581a5deef7b2876b0c3774635b8d846c
Author: Yinghai Lu <yinghai(a)kernel.org>
AuthorDate: Wed, 14 Jul 2010 11:26:57 -0700
Committer: H. Peter Anvin <hpa(a)linux.intel.com>
CommitDate: Wed, 14 Jul 2010 12:07:16 -0700

x86, setup: Only set early_serial_base after port is initialized

putchar is using early_serial_base to check if port is initialized.

So we only assign it after early_serial_init() is called,
in case we need use VGA to debug early serial console.

Also add display for port addr and baud.

-v2: update to current tip

Acked-by: Pekka Enberg <penberg(a)cs.helsinki.fi>
Signed-off-by: Yinghai Lu <yinghai(a)kernel.org>
LKML-Reference: <4C3E0171.6050008(a)kernel.org>
Signed-off-by: H. Peter Anvin <hpa(a)linux.intel.com>
---
arch/x86/boot/tty.c | 63 ++++++++++++++++++++++++++------------------------
1 files changed, 33 insertions(+), 30 deletions(-)

diff --git a/arch/x86/boot/tty.c b/arch/x86/boot/tty.c
index f6d52e6..ff4b27a 100644
--- a/arch/x86/boot/tty.c
+++ b/arch/x86/boot/tty.c
@@ -152,35 +152,40 @@ int getchar_timeout(void)
return 0; /* Timeout! */
}

-static void early_serial_init(int baud)
+static void early_serial_init(int port, int baud)
{
unsigned char c;
unsigned divisor;

- outb(0x3, early_serial_base + LCR); /* 8n1 */
- outb(0, early_serial_base + IER); /* no interrupt */
- outb(0, early_serial_base + FCR); /* no fifo */
- outb(0x3, early_serial_base + MCR); /* DTR + RTS */
+ outb(0x3, port + LCR); /* 8n1 */
+ outb(0, port + IER); /* no interrupt */
+ outb(0, port + FCR); /* no fifo */
+ outb(0x3, port + MCR); /* DTR + RTS */

divisor = 115200 / baud;
- c = inb(early_serial_base + LCR);
- outb(c | DLAB, early_serial_base + LCR);
- outb(divisor & 0xff, early_serial_base + DLL);
- outb((divisor >> 8) & 0xff, early_serial_base + DLH);
- outb(c & ~DLAB, early_serial_base + LCR);
+ c = inb(port + LCR);
+ outb(c | DLAB, port + LCR);
+ outb(divisor & 0xff, port + DLL);
+ outb((divisor >> 8) & 0xff, port + DLH);
+ outb(c & ~DLAB, port + LCR);
+
+ early_serial_base = port;
+
+ printf("Early serial console at I/O port 0x%x baud: %d\n", port, baud);
}

-static int parse_earlyprintk(void)
+static void parse_earlyprintk(void)
{
int baud = DEFAULT_BAUD;
char arg[32];
int pos = 0;
+ int port = 0;

if (cmdline_find_option("earlyprintk", arg, sizeof arg) > 0) {
char *e;

if (!strncmp(arg, "serial", 6)) {
- early_serial_base = DEFAULT_SERIAL_PORT;
+ port = DEFAULT_SERIAL_PORT;
pos += 6;
}

@@ -189,15 +194,15 @@ static int parse_earlyprintk(void)

if (!strncmp(arg, "ttyS", 4)) {
static const int bases[] = { 0x3f8, 0x2f8 };
- int port = 0;
+ int idx = 0;

if (!strncmp(arg + pos, "ttyS", 4))
pos += 4;

if (arg[pos++] == '1')
- port = 1;
+ idx = 1;

- early_serial_base = bases[port];
+ port = bases[idx];
}

if (arg[pos] == ',')
@@ -208,7 +213,8 @@ static int parse_earlyprintk(void)
baud = DEFAULT_BAUD;
}

- return baud;
+ if (port)
+ early_serial_init(port, baud);
}

#define BASE_BAUD (1843200/16)
@@ -227,44 +233,41 @@ static unsigned int probe_baud(int port)
return BASE_BAUD / quot;
}

-static int parse_console_uart8250(void)
+static void parse_console_uart8250(void)
{
char optstr[64], *options;
int baud = DEFAULT_BAUD;
+ int port = 0;

/*
* console=uart8250,io,0x3f8,115200n8
* need to make sure it is last one console !
*/
if (cmdline_find_option("console", optstr, sizeof optstr) <= 0)
- return baud;
+ return;

options = optstr;

if (!strncmp(options, "uart8250,io,", 12))
- early_serial_base = simple_strtoull(options + 12, &options, 0);
+ port = simple_strtoull(options + 12, &options, 0);
else if (!strncmp(options, "uart,io,", 8))
- early_serial_base = simple_strtoull(options + 8, &options, 0);
+ port = simple_strtoull(options + 8, &options, 0);
else
- return baud;
+ return;

if (options && (options[0] == ','))
baud = simple_strtoull(options + 1, &options, 0);
else
- baud = probe_baud(early_serial_base);
+ baud = probe_baud(port);

- return baud;
+ if (port)
+ early_serial_init(port, baud);
}

void console_init(void)
{
- int baud;
-
- baud = parse_earlyprintk();
+ parse_earlyprintk();

if (!early_serial_base)
- baud = parse_console_uart8250();
-
- if (early_serial_base != 0)
- early_serial_init(baud);
+ parse_console_uart8250();
}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
 | 
Pages: 1
Prev: cfq-iosched: don't allow aliased requests to starve others
Next: Removing dead {AR,WAVE}LAN