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| author | Len Brown <len.brown@intel.com> | 2009-04-17 23:32:20 -0400 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2009-04-17 23:32:20 -0400 |
| commit | 96f15efcea94545987715f453a8c2b8ea592d000 (patch) | |
| tree | 9dac5a4547357e311cc2be960b799a91ae3ee15d /drivers/acpi/sleep.c | |
| parent | 0882e8dd3aad33eca41696d463bb896e6c8817eb (diff) | |
| download | kernel-crypto-96f15efcea94545987715f453a8c2b8ea592d000.tar.gz kernel-crypto-96f15efcea94545987715f453a8c2b8ea592d000.tar.xz kernel-crypto-96f15efcea94545987715f453a8c2b8ea592d000.zip | |
ACPI: Disable _GTS and _BFS support by default
Executing BIOS code paths not exercised by Windows
tends to get Linux into trouble.
However, if a system does benefit from _GTS or _BFS,
acpi.gts=1 an acpi.bfs=1 are now available to enable them.
http://bugzilla.kernel.org/show_bug.cgi?id=13041
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/sleep.c')
| -rw-r--r-- | drivers/acpi/sleep.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c index 779e4e500df..9042875ac94 100644 --- a/drivers/acpi/sleep.c +++ b/drivers/acpi/sleep.c @@ -713,6 +713,32 @@ static void acpi_power_off(void) acpi_enter_sleep_state(ACPI_STATE_S5); } +/* + * ACPI 2.0 created the optional _GTS and _BFS, + * but industry adoption has been neither rapid nor broad. + * + * Linux gets into trouble when it executes poorly validated + * paths through the BIOS, so disable _GTS and _BFS by default, + * but do speak up and offer the option to enable them. + */ +void __init acpi_gts_bfs_check(void) +{ + acpi_handle dummy; + + if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__GTS, &dummy))) + { + printk(KERN_NOTICE PREFIX "BIOS offers _GTS\n"); + printk(KERN_NOTICE PREFIX "If \"acpi.gts=1\" improves suspend, " + "please notify linux-acpi@vger.kernel.org\n"); + } + if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__BFS, &dummy))) + { + printk(KERN_NOTICE PREFIX "BIOS offers _BFS\n"); + printk(KERN_NOTICE PREFIX "If \"acpi.bfs=1\" improves resume, " + "please notify linux-acpi@vger.kernel.org\n"); + } +} + int __init acpi_sleep_init(void) { acpi_status status; @@ -771,5 +797,6 @@ int __init acpi_sleep_init(void) * object can also be evaluated when the system enters S5. */ register_reboot_notifier(&tts_notifier); + acpi_gts_bfs_check(); return 0; } |