ACPI: Make _OSI(Linux) a special case

_OSI("Linux") is like _OS("Linux"), it is ill-defined and
virtually no BIOS vendors test interaction with it.
As a result, it can do more damage than good because
it causes the BIOS to follow un-tested paths.

Recently, several machines have turned up that erroneously
test this string in a way which causes them to _not_ test other
compatibility strings, including the ZI9 and Toshiba.
So it appears that this bad code has made it into
a BIOS vendor's reference BIOS.

Linux has no choice but to stop advertising compatibility
with _OSI string "Linux" - as there are an unbounded
number of possible incompatibilities going forward.

But some BIOSes have already shipped which do use it
for things like conditionally re-enabling video on resume
from S3.  (Too bad they didn't do that unconditionally)

Add special case code for _OSI(Linux)
Squawk to dmesg if _OSI(Linux) is requested
Add DMI list both to enable and disable _OSI(Linux)
But for now, keep the default enabled via
#define OSI_LINUX_ENABLED.

http://bugzilla.kernel.org/show_bug.cgi?id=7787

Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Len Brown 2007-05-30 00:10:38 -04:00
parent ae00d81243
commit f507654d45
2 changed files with 91 additions and 1 deletions

View file

@ -33,6 +33,7 @@
#include <linux/interrupt.h>
#include <linux/kmod.h>
#include <linux/delay.h>
#include <linux/dmi.h>
#include <linux/workqueue.h>
#include <linux/nmi.h>
#include <linux/acpi.h>
@ -76,6 +77,18 @@ static struct workqueue_struct *kacpi_notify_wq;
#define OSI_STRING_LENGTH_MAX 64 /* arbitrary */
static char osi_additional_string[OSI_STRING_LENGTH_MAX];
#define OSI_LINUX_ENABLED
#ifdef OSI_LINUX_ENABLED
int osi_linux = 1; /* enable _OSI(Linux) by default */
#else
int osi_linux; /* disable _OSI(Linux) by default */
#endif
#ifdef CONFIG_DMI
static struct dmi_system_id acpi_osl_dmi_table[];
#endif
static void __init acpi_request_region (struct acpi_generic_address *addr,
unsigned int length, char *desc)
{
@ -126,6 +139,7 @@ device_initcall(acpi_reserve_resources);
acpi_status acpi_os_initialize(void)
{
dmi_check_system(acpi_osl_dmi_table);
return AE_OK;
}
@ -963,6 +977,16 @@ static int __init acpi_os_name_setup(char *str)
__setup("acpi_os_name=", acpi_os_name_setup);
static void enable_osi_linux(int enable) {
if (osi_linux != enable)
printk(KERN_INFO PREFIX "%sabled _OSI(Linux)\n",
enable ? "En": "Dis");
osi_linux = enable;
return;
}
/*
* Modify the list of "OS Interfaces" reported to BIOS via _OSI
*
@ -978,6 +1002,10 @@ static int __init acpi_osi_setup(char *str)
} else if (*str == '!') {
if (acpi_osi_invalidate(++str) == AE_OK)
printk(KERN_INFO PREFIX "Deleted _OSI(%s)\n", str);
} else if (!strcmp("!Linux", str)) {
enable_osi_linux(0);
} else if (!strcmp("Linux", str)) {
enable_osi_linux(1);
} else if (*osi_additional_string == '\0') {
strncpy(osi_additional_string, str, OSI_STRING_LENGTH_MAX);
printk(KERN_INFO PREFIX "Added _OSI(%s)\n", str);
@ -1152,6 +1180,23 @@ acpi_os_validate_interface (char *interface)
{
if (!strncmp(osi_additional_string, interface, OSI_STRING_LENGTH_MAX))
return AE_OK;
if (!strcmp("Linux", interface)) {
printk(KERN_WARNING PREFIX
"System BIOS is requesting _OSI(Linux)\n");
#ifdef OSI_LINUX_ENABLED
printk(KERN_WARNING PREFIX
"Please test with \"acpi_osi=!Linux\"\n"
"Please send dmidecode "
"to linux-acpi@vger.kernel.org\n");
#else
printk(KERN_WARNING PREFIX
"If \"acpi_osi=Linux\" works better,\n"
"Please send dmidecode "
"to linux-acpi@vger.kernel.org\n");
#endif
if(osi_linux)
return AE_OK;
}
return AE_SUPPORT;
}
@ -1181,5 +1226,51 @@ acpi_os_validate_address (
return AE_OK;
}
#ifdef CONFIG_DMI
#ifdef OSI_LINUX_ENABLED
static int dmi_osi_not_linux(struct dmi_system_id *d)
{
printk(KERN_NOTICE "%s detected: requires not _OSI(Linux)\n", d->ident);
enable_osi_linux(0);
return 0;
}
#else
static int dmi_osi_linux(struct dmi_system_id *d)
{
printk(KERN_NOTICE "%s detected: requires _OSI(Linux)\n", d->ident);
enable_osi_linux(1);
return 0;
}
#endif
static struct dmi_system_id acpi_osl_dmi_table[] = {
#ifdef OSI_LINUX_ENABLED
/*
* Boxes that need NOT _OSI(Linux)
*/
{
.callback = dmi_osi_not_linux,
.ident = "Toshiba Satellite P100",
.matches = {
DMI_MATCH(DMI_BOARD_VENDOR, "TOSHIBA"),
DMI_MATCH(DMI_BOARD_NAME, "Satellite P100"),
},
},
#else
/*
* Boxes that need _OSI(Linux)
*/
{
.callback = dmi_osi_linux,
.ident = "Intel Napa CRB",
.matches = {
DMI_MATCH(DMI_BOARD_VENDOR, "Intel Corporation"),
DMI_MATCH(DMI_BOARD_NAME, "MPAD-MSAE Customer Reference Boards"),
},
},
#endif
{}
};
#endif /* CONFIG_DMI */
#endif

View file

@ -62,7 +62,6 @@ acpi_ut_translate_one_cid(union acpi_operand_object *obj_desc,
static char *acpi_interfaces_supported[] = {
/* Operating System Vendor Strings */
"Linux",
"Windows 2000",
"Windows 2001",
"Windows 2001 SP0",