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authorLen Brown <len.brown@intel.com>2009-04-17 23:32:20 -0400
committerLen Brown <len.brown@intel.com>2009-04-17 23:32:20 -0400
commit96f15efcea94545987715f453a8c2b8ea592d000 (patch)
tree9dac5a4547357e311cc2be960b799a91ae3ee15d
parent0882e8dd3aad33eca41696d463bb896e6c8817eb (diff)
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>
-rw-r--r--drivers/acpi/acpica/hwsleep.c43
-rw-r--r--drivers/acpi/sleep.c27
2 files changed, 53 insertions, 17 deletions
diff --git a/drivers/acpi/acpica/hwsleep.c b/drivers/acpi/acpica/hwsleep.c
index baa5fc05e12..db307a356f0 100644
--- a/drivers/acpi/acpica/hwsleep.c
+++ b/drivers/acpi/acpica/hwsleep.c
@@ -211,6 +211,12 @@ acpi_status acpi_enter_sleep_state_prep(u8 sleep_state)
ACPI_EXPORT_SYMBOL(acpi_enter_sleep_state_prep)
+static unsigned int gts, bfs;
+module_param(gts, uint, 0644);
+module_param(bfs, uint, 0644);
+MODULE_PARM_DESC(gts, "Enable evaluation of _GTS on suspend.");
+MODULE_PARM_DESC(bfs, "Enable evaluation of _BFS on resume".);
+
/*******************************************************************************
*
* FUNCTION: acpi_enter_sleep_state
@@ -278,16 +284,18 @@ acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state)
return_ACPI_STATUS(status);
}
- /* Execute the _GTS method */
+ if (gts) {
+ /* Execute the _GTS method */
- arg_list.count = 1;
- arg_list.pointer = &arg;
- arg.type = ACPI_TYPE_INTEGER;
- arg.integer.value = sleep_state;
+ arg_list.count = 1;
+ arg_list.pointer = &arg;
+ arg.type = ACPI_TYPE_INTEGER;
+ arg.integer.value = sleep_state;
- status = acpi_evaluate_object(NULL, METHOD_NAME__GTS, &arg_list, NULL);
- if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
- return_ACPI_STATUS(status);
+ status = acpi_evaluate_object(NULL, METHOD_NAME__GTS, &arg_list, NULL);
+ if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+ return_ACPI_STATUS(status);
+ }
}
/* Get current value of PM1A control */
@@ -513,18 +521,19 @@ acpi_status acpi_leave_sleep_state_prep(u8 sleep_state)
}
}
- /* Execute the _BFS method */
+ if (bfs) {
+ /* Execute the _BFS method */
- arg_list.count = 1;
- arg_list.pointer = &arg;
- arg.type = ACPI_TYPE_INTEGER;
- arg.integer.value = sleep_state;
+ arg_list.count = 1;
+ arg_list.pointer = &arg;
+ arg.type = ACPI_TYPE_INTEGER;
+ arg.integer.value = sleep_state;
- status = acpi_evaluate_object(NULL, METHOD_NAME__BFS, &arg_list, NULL);
- if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
- ACPI_EXCEPTION((AE_INFO, status, "During Method _BFS"));
+ status = acpi_evaluate_object(NULL, METHOD_NAME__BFS, &arg_list, NULL);
+ if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+ ACPI_EXCEPTION((AE_INFO, status, "During Method _BFS"));
+ }
}
-
return_ACPI_STATUS(status);
}
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;
}