diff options
| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2026-01-13 14:36:54 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2026-01-13 23:10:25 +0100 |
| commit | 7edf6f7ef5345e1b4202912ca98aaa7c73e1e82c (patch) | |
| tree | d272a2eeec2b3b8e0b12e0d3438eb34ac6ac0166 | |
| parent | 8f334e35220721f65180bc2e0fe9187436c2c475 (diff) | |
ACPI: PM: s2idle: Add module parameter for LPS0 constraints checking
Commit 32ece31db4df ("ACPI: PM: s2idle: Only retrieve constraints when
needed") attempted to avoid useless evaluation of LPS0 _DSM Function 1
in lps0_device_attach() because pm_debug_messages_on might never be set
(and that is the case on production systems most of the time), but it
turns out that LPS0 _DSM Function 1 is generally problematic on some
platforms and causes suspend issues to occur when pm_debug_messages_on
is set now.
In Linux, LPS0 _DSM Function 1 is only useful for diagnostics and only
in the cases when the system does not reach the deepest platform idle
state during suspend-to-idle for some reason. If such diagnostics is
not necessary, evaluating it is a loss of time, so using it along with
the other pm_debug_messages_on diagnostics is questionable because the
latter is expected to be suitable for collecting debug information even
during production use of system suspend.
For this reason, add a module parameter called check_lps0_constraints
to control whether or not the list of LPS0 constraints will be checked
in acpi_s2idle_prepare_late_lps0() and so whether or not to evaluate
LPS0 _DSM Function 1 (once) in acpi_s2idle_begin_lps0().
Fixes: 32ece31db4df ("ACPI: PM: s2idle: Only retrieve constraints when needed")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Link: https://patch.msgid.link/2827214.mvXUDI8C0e@rafael.j.wysocki
| -rw-r--r-- | drivers/acpi/x86/s2idle.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/acpi/x86/s2idle.c b/drivers/acpi/x86/s2idle.c index 2a9edb53d5d4..cc3c83e4cc23 100644 --- a/drivers/acpi/x86/s2idle.c +++ b/drivers/acpi/x86/s2idle.c @@ -28,6 +28,10 @@ static bool sleep_no_lps0 __read_mostly; module_param(sleep_no_lps0, bool, 0644); MODULE_PARM_DESC(sleep_no_lps0, "Do not use the special LPS0 device interface"); +static bool check_lps0_constraints __read_mostly; +module_param(check_lps0_constraints, bool, 0644); +MODULE_PARM_DESC(check_lps0_constraints, "Check LPS0 device constraints"); + static const struct acpi_device_id lps0_device_ids[] = { {"PNP0D80", }, {"", }, @@ -515,7 +519,7 @@ static struct acpi_scan_handler lps0_handler = { static int acpi_s2idle_begin_lps0(void) { - if (lps0_device_handle && !sleep_no_lps0 && pm_debug_messages_on && + if (lps0_device_handle && !sleep_no_lps0 && check_lps0_constraints && !lpi_constraints_table) { if (acpi_s2idle_vendor_amd()) lpi_device_get_constraints_amd(); @@ -540,7 +544,7 @@ static int acpi_s2idle_prepare_late_lps0(void) if (!lps0_device_handle || sleep_no_lps0) return 0; - if (pm_debug_messages_on) + if (check_lps0_constraints) lpi_check_constraints(); /* Screen off */ |