4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Lv Zheng <lv.zheng@xxxxxxxxx>
[ Upstream commit 77e9a4aa9de10cc1418bf9a892366988802a8025 ]
More and more platforms need the button.lid_init_state=open quirk. This
patch sets it the default behavior.
If a platform doesn't send lid open event or lid open event is lost due to
the underlying system problems, then we can compare various combinations:
1. systemd/acpid is used to suspend system or not, systemd has a special
logic forcing open event after resuming;
2. _LID returns a cached value or not.
The result is as follows:
1. lid_init_state=method
1. cached
1. resumed by lid:
(x) event=close
(x) systemd=suspends again
(x) acpid=suspends again
(x) state=close
2. resumed by other:
(o) event=close
(x) systemd=suspends again
(x) acpid=suspends again
(o) state=close
2. non-cached
1. resumed by lid:
(o) event=open
(o) systemd=resumes
(o) acpid=resumes
(o) state=open
2. resumed by other:
(o) event=close
(x) systemd=suspends again
(x) acpid=suspends again
(o) state=close
2. lid_init_state=open
1. cached
1. resumed by lid:
(o) event=open
(o) systemd=resumes
(o) acpid=resumes
(x) state=close
2. resumed by other:
(x) event=open
(o) systemd=resumes
(o) acpid=resumes
(o) state=close
2. non-cached
1. resumed by lid:
(o) event=open
(o) systemd=resumes
(o) acpid=resumes
(o) state=open
2. resumed by other:
(x) event=open
(o) systemd=resumes
(o) acpid=resumes
(o) state=close
3. lid_init_state=ignore
1. cached
1. resumed by lid:
(o) event=none
(x) systemd=suspends again
(o) acpid=resumes
(x) state=close
2. resumed by other:
(o) event=none
(x) systemd=suspends again
(o) acpid=resumes
(o) state=close
2. non-cached
1. resumed by lid:
(o) event=none
(x) systemd=suspends again
(o) acpid=resumes
(o) state=open
2. resumed by other:
(o) event=none
(x) systemd=suspends again
(o) acpid=resumes
(o) state=close
As a conclusion:
1. With systemd changed, lid_init_state=ignore has only one problem and the
problem comes from an underlying issue, not userspace and kernel lid
handling.
2. Without systemd changed, lid_init_state=open can be the default
behavior as the pass ratio is not much worse than lid_init_state=ignore.
3. lid_init_state=method is buggy, we can have a separate patch to make it
deprectated.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=187271
Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/acpi/button.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -113,7 +113,7 @@ struct acpi_button {
static BLOCKING_NOTIFIER_HEAD(acpi_lid_notifier);
static struct acpi_device *lid_device;
-static u8 lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;
+static u8 lid_init_state = ACPI_BUTTON_LID_INIT_OPEN;
static unsigned long lid_report_interval __read_mostly = 500;
module_param(lid_report_interval, ulong, 0644);