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authorLv Zheng <lv.zheng@intel.com>2017-01-12 10:47:34 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-01-31 19:20:44 +0300
commit77e9a4aa9de10cc1418bf9a892366988802a8025 (patch)
tree358a6ba21dacc336ce9282c7b8385c5f463f53fd /Documentation/fpga
parent566cf877a1fcb6d6dc0126b076aad062054c2637 (diff)
downloadlinux-77e9a4aa9de10cc1418bf9a892366988802a8025.tar.xz
ACPI / button: Change default behavior to lid_init_state=open
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@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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