3c274c2909
reported by mereandor@gmail.com, in: http://bugzilla.kernel.org/show_bug.cgi?id=6307 Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
122 lines
2.8 KiB
C
122 lines
2.8 KiB
C
/*
|
|
* I/O delay strategies for inb_p/outb_p
|
|
*
|
|
* Allow for a DMI based override of port 0x80, needed for certain HP laptops
|
|
* and possibly other systems. Also allow for the gradual elimination of
|
|
* outb_p/inb_p API uses.
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/dmi.h>
|
|
#include <asm/io.h>
|
|
|
|
int io_delay_type __read_mostly = CONFIG_DEFAULT_IO_DELAY_TYPE;
|
|
|
|
static int __initdata io_delay_override;
|
|
|
|
/*
|
|
* Paravirt wants native_io_delay to be a constant.
|
|
*/
|
|
void native_io_delay(void)
|
|
{
|
|
switch (io_delay_type) {
|
|
default:
|
|
case CONFIG_IO_DELAY_TYPE_0X80:
|
|
asm volatile ("outb %al, $0x80");
|
|
break;
|
|
case CONFIG_IO_DELAY_TYPE_0XED:
|
|
asm volatile ("outb %al, $0xed");
|
|
break;
|
|
case CONFIG_IO_DELAY_TYPE_UDELAY:
|
|
/*
|
|
* 2 usecs is an upper-bound for the outb delay but
|
|
* note that udelay doesn't have the bus-level
|
|
* side-effects that outb does, nor does udelay() have
|
|
* precise timings during very early bootup (the delays
|
|
* are shorter until calibrated):
|
|
*/
|
|
udelay(2);
|
|
case CONFIG_IO_DELAY_TYPE_NONE:
|
|
break;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(native_io_delay);
|
|
|
|
static int __init dmi_io_delay_0xed_port(const struct dmi_system_id *id)
|
|
{
|
|
if (io_delay_type == CONFIG_IO_DELAY_TYPE_0X80) {
|
|
printk(KERN_NOTICE "%s: using 0xed I/O delay port\n",
|
|
id->ident);
|
|
io_delay_type = CONFIG_IO_DELAY_TYPE_0XED;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Quirk table for systems that misbehave (lock up, etc.) if port
|
|
* 0x80 is used:
|
|
*/
|
|
static struct dmi_system_id __initdata io_delay_0xed_port_dmi_table[] = {
|
|
{
|
|
.callback = dmi_io_delay_0xed_port,
|
|
.ident = "Compaq Presario V6000",
|
|
.matches = {
|
|
DMI_MATCH(DMI_BOARD_VENDOR, "Quanta"),
|
|
DMI_MATCH(DMI_BOARD_NAME, "30B7")
|
|
}
|
|
},
|
|
{
|
|
.callback = dmi_io_delay_0xed_port,
|
|
.ident = "HP Pavilion dv9000z",
|
|
.matches = {
|
|
DMI_MATCH(DMI_BOARD_VENDOR, "Quanta"),
|
|
DMI_MATCH(DMI_BOARD_NAME, "30B9")
|
|
}
|
|
},
|
|
{
|
|
.callback = dmi_io_delay_0xed_port,
|
|
.ident = "HP Pavilion dv6000",
|
|
.matches = {
|
|
DMI_MATCH(DMI_BOARD_VENDOR, "Quanta"),
|
|
DMI_MATCH(DMI_BOARD_NAME, "30B8")
|
|
}
|
|
},
|
|
{
|
|
.callback = dmi_io_delay_0xed_port,
|
|
.ident = "HP Pavilion tx1000",
|
|
.matches = {
|
|
DMI_MATCH(DMI_BOARD_VENDOR, "Quanta"),
|
|
DMI_MATCH(DMI_BOARD_NAME, "30BF")
|
|
}
|
|
},
|
|
{ }
|
|
};
|
|
|
|
void __init io_delay_init(void)
|
|
{
|
|
if (!io_delay_override)
|
|
dmi_check_system(io_delay_0xed_port_dmi_table);
|
|
}
|
|
|
|
static int __init io_delay_param(char *s)
|
|
{
|
|
if (!strcmp(s, "0x80"))
|
|
io_delay_type = CONFIG_IO_DELAY_TYPE_0X80;
|
|
else if (!strcmp(s, "0xed"))
|
|
io_delay_type = CONFIG_IO_DELAY_TYPE_0XED;
|
|
else if (!strcmp(s, "udelay"))
|
|
io_delay_type = CONFIG_IO_DELAY_TYPE_UDELAY;
|
|
else if (!strcmp(s, "none"))
|
|
io_delay_type = CONFIG_IO_DELAY_TYPE_NONE;
|
|
else
|
|
return -EINVAL;
|
|
|
|
io_delay_override = 1;
|
|
return 0;
|
|
}
|
|
|
|
early_param("io_delay", io_delay_param);
|