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>
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index f4760cf..e349879d 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -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 @@
#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 @@
acpi_status acpi_os_initialize(void)
{
+ dmi_check_system(acpi_osl_dmi_table);
return AE_OK;
}
@@ -963,6 +977,16 @@
__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 @@
} 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 @@
{
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 @@
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
diff --git a/drivers/acpi/utilities/uteval.c b/drivers/acpi/utilities/uteval.c
index a10120a..8ec6f8e 100644
--- a/drivers/acpi/utilities/uteval.c
+++ b/drivers/acpi/utilities/uteval.c
@@ -62,7 +62,6 @@
static char *acpi_interfaces_supported[] = {
/* Operating System Vendor Strings */
- "Linux",
"Windows 2000",
"Windows 2001",
"Windows 2001 SP0",