From: Len Brown <len.brown@xxxxxxxxx> 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@xxxxxxxxx> --- yeah, i know, i scribbled a linux modparam into an ACPICA file. i did it because i wanted the flags to static to avoid namespace pollution. drivers/acpi/acpica/hwsleep.c | 43 ++++++++++++++++++++++++---------------- drivers/acpi/sleep.c | 27 +++++++++++++++++++++++++ 2 files changed, 53 insertions(+), 17 deletions(-) diff --git a/drivers/acpi/acpica/hwsleep.c b/drivers/acpi/acpica/hwsleep.c index baa5fc0..db307a3 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 779e4e5..9042875 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@xxxxxxxxxxxxxxx\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@xxxxxxxxxxxxxxx\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; } -- 1.6.3.rc0.1.gf800 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
