ACPI: make _OSI(Linux) console messages smarter

If BIOS invokes _OSI(Linux), the kernel response
depends on what the ACPI DMI list knows about the system,
and that is reflectd in dmesg:

1) System unknown to DMI:

ACPI: BIOS _OSI(Linux) query ignored
ACPI: DMI System Vendor: LENOVO
ACPI: DMI Product Name: 7661W1P
ACPI: DMI Product Version: ThinkPad T61
ACPI: DMI Board Name: 7661W1P
ACPI: DMI BIOS Vendor: LENOVO
ACPI: DMI BIOS Date: 10/18/2007
ACPI: Please send DMI info above to linux-acpi@vger.kernel.org
ACPI: If "acpi_osi=Linux" works better, please notify linux-acpi@vger.kernel.org

2) System known to DMI, but effect of OSI(Linux) unknown:

ACPI: DMI detected: Lenovo ThinkPad T61
...
ACPI: BIOS _OSI(Linux) query ignored via DMI
ACPI: If "acpi_osi=Linux" works better, please notify linux-acpi@vger.kernel.org

3) System known to DMI, which disables _OSI(Linux):

ACPI: DMI detected: Lenovo ThinkPad T61
...
ACPI: BIOS _OSI(Linux) query ignored via DMI

4) System known to DMI, which enable _OSI(Linux):

ACPI: DMI detected: Lenovo ThinkPad T61
ACPI: Added _OSI(Linux)
...
ACPI: BIOS _OSI(Linux) query honored via DMI

cmdline overrides take precidence over the built-in
default and the DMI prescribed default.
cmdline "acpi_osi=Linux" results in:

ACPI: BIOS _OSI(Linux) query honored via cmdline

Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/acpi/blacklist.c b/drivers/acpi/blacklist.c
index 3ec110ce00c8..018fc16c44ce 100644
--- a/drivers/acpi/blacklist.c
+++ b/drivers/acpi/blacklist.c
@@ -3,6 +3,7 @@
  *
  *  Check to see if the given machine has a known bad ACPI BIOS
  *  or if the BIOS is too old.
+ *  Check given machine against acpi_osi_dmi_table[].
  *
  *  Copyright (C) 2004 Len Brown <len.brown@intel.com>
  *  Copyright (C) 2002 Andy Grover <andrew.grover@intel.com>
@@ -50,6 +51,8 @@ struct acpi_blacklist_item {
         u32 is_critical_error;
 };
 
+static struct dmi_system_id acpi_osi_dmi_table[] __initdata;
+
 /*
  * POLICY: If *anything* doesn't work, put it on the blacklist.
  *         If they are critical errors, mark it critical, and abort driver load.
@@ -165,5 +168,13 @@ int __init acpi_blacklisted(void)
 
         blacklisted += blacklist_by_year();
 
+        dmi_check_system(acpi_osi_dmi_table);
+
         return blacklisted;
 }
+#ifdef CONFIG_DMI
+static struct dmi_system_id acpi_osi_dmi_table[] __initdata = {
+        {}
+};
+
+#endif /* CONFIG_DMI */