Commit 96f15efc authored by Len Brown's avatar Len Brown

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=13041Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 0882e8dd
......@@ -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);
}
......
......@@ -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;
}
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