kernel/linux.git/drivers/acpi/button.c, branch v4.11.5

Revert "ACPI / button: Change default behavior to lid_init_state=open"

2017-06-07T10:10:08+00:00

commit 878d8db039daac0938238e9a40a5bd6e50ee3c9b upstream. Revert commit 77e9a4aa9de1 (ACPI / button: Change default behavior to lid_init_state=open) which changed the kernel's behavior on laptops that boot with closed lids and expect the lid switch state to be reported accurately by the kernel. If you boot or resume your laptop with the lid closed on a docking station while using an external monitor connected to it, both internal and external displays will light on, while only the external should. There is a design choice in gdm to only provide the greeter on the internal display when lit on, so users only see a gray area on the external monitor. Also, the cursor will not show up as it's by default on the internal display too. To "fix" that, users have to open the laptop once and close it once again to sync the state of the switch with the hardware state. Even if the "method" operation mode implementation can be buggy on some platforms, the "open" choice is worse. It breaks docking stations basically and there is no way to have a user-space hwdb to fix that. On the contrary, it's rather easy in user-space to have a hwdb with the problematic platforms. Then, libinput (1.7.0+) can fix the state of the lid switch for us: you need to set the udev property LIBINPUT_ATTR_LID_SWITCH_RELIABILITY to 'write_open'. When libinput detects internal keyboard events, it will overwrite the state of the switch to open, making it reliable again. Given that logind only checks the lid switch value after a timeout, we can assume the user will use the internal keyboard before this timeout expires. For example, such a hwdb entry is: libinput:name:*Lid Switch*:dmi:*svnMicrosoftCorporation:pnSurface3:* LIBINPUT_ATTR_LID_SWITCH_RELIABILITY=write_open Link: https://bugzilla.gnome.org/show_bug.cgi?id=782380 Signed-off-by: Benjamin Tissoires Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

Revert "ACPI / button: Remove lid_init_state=method mode"

2017-06-07T10:10:07+00:00

commit f369fdf4f661322b73f3307e9f3cd55fb3a20123 upstream. This reverts commit ecb10b694b72ca5ea51b3c90a71ff2a11963425a. The only expected ACPI control method lid device's usage model is 1. Listen to the lid notification, 2. Evaluate _LID after being notified by BIOS, 3. Suspend the system (if users configure to do so) after seeing "close". It's not ensured that BIOS will notify OS after boot/resume, and it's not ensured that BIOS will always generate "open" event upon opening the lid. But there are 2 wrong usage models: 1. When the lid device is responsible for suspend/resume the system, userspace requires to see "open" event to be paired with "close" after the system is resumed, or it will suspend the system again. 2. When an external monitor connects to the laptop attached docks, userspace requires to see "close" event after the system is resumed so that it can determine whether the internal display should remain dark and the external display should be lit on. After we made default kernel behavior to be suitable for usage model 1, users of usage model 2 start to report regressions for such behavior change. Reversion of button.lid_init_state=method doesn't actually reverts to old default behavior as doing so can enter a regression loop, but facilitates users to work the reported regressions around with button.lid_init_state=method. Fixes: ecb10b694b72 (ACPI / button: Remove lid_init_state=method mode) Link: https://bugzilla.kernel.org/show_bug.cgi?id=195455 Link: https://bugzilla.redhat.com/show_bug.cgi?id=1430259 Tested-by: Steffen Weber Tested-by: Julian Wiedmann Reported-by: Joachim Frieben Signed-off-by: Lv Zheng Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

ACPI / button: Remove lid_init_state=method mode

2017-01-31T16:20:45+00:00

The mode is buggy, and lid_init__state=open is more useful than this mode, so this patch makes it deprecated. Signed-off-by: Lv Zheng Signed-off-by: Rafael J. Wysocki

ACPI / button: Change default behavior to lid_init_state=open

2017-01-31T16:20:44+00:00

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 Signed-off-by: Rafael J. Wysocki

ACPI / button: Fix an issue in button.lid_init_state=ignore mode

2016-08-30T23:06:20+00:00

On most platforms, _LID returning value, lid open/close events are all reliable, but there are exceptions. Some AML tables report wrong initial lid state [1], and some of them never report lid open state [2]. The usage model on such buggy platforms is: 1. The initial lid state returned from _LID is not reliable; 2. The lid open event is not reliable; 3. The lid close event is always reliable, used by the platform firmware to trigger OSPM power saving operations. This usage model is not compliant to the Linux SW_LID model as the Linux userspace is very strict to the reliability of the open events. In order not to trigger issues on such buggy platforms, the ACPI button driver currently implements a lid_init_state=open quirk to send additional "open" event after resuming. However, this is still not sufficient because: 1. Some special usage models (e.x., the dark resume scenario) cannot be supported by this mode. 2. If a "close" event is not used to trigger "suspend", then the subsequent "close" events cannot be seen by the userspace. So we need to stop sending the additional "open" event and switch the driver to lid_init_state=ignore mode and make sure the platform triggered events can be reliably delivered to the userspace. The userspace programs then can be changed to not to be strict to the "open" events on such buggy platforms. Why will the subsequent "close" events be lost? This is because the input layer automatically filters redundant events for switch events. Thus given that the buggy AML tables do not guarantee paired "open"/"close" events, the ACPI button driver currently is not able to guarantee that the platform triggered reliable events can be always be seen by the userspace via SW_LID. This patch adds a mechanism to insert lid events as a compensation for the platform triggered ones to form a complete event switches in order to make sure that the platform triggered events can always be reliably delivered to the userspace. This essentially guarantees that the platform triggered reliable "close" events will always be relibly delivered to the userspace. However this mechanism is not suitable for lid_init_state=open/method as it should not send the complement switch event for the unreliable initial lid state notification. 2 unreliable events can trigger unexpected behavior. Thus this patch only implements this mechanism for lid_init_state=ignore. Known issues: 1. Possible alternative approach This approach is based on the fact that Linux requires a switch event type for LID events. Another approach is to use key event type to implement ACPI lid events. With SW event type, since ACPI button driver inserts wrong lid events, there could be a potential issue that an "open" event issued from some AML update methods could result in a wrong "close" event to be delivered to the userspace. While using KEY event type, there is no such problem. However there may not be such a kind of real case, and if there is such a case, it is worked around in this patch as the complement switch event is only generated for "close" event in order to deliver the reliable "close" event to the userspace. Link: https://bugzilla.kernel.org/show_bug.cgi?id=89211 # [1] Link: https://bugzilla.kernel.org/show_bug.cgi?id=106151 # [1] Link: https://bugzilla.kernel.org/show_bug.cgi?id=106941 # [2] Signed-off-by: Lv Zheng Suggested-by: Dmitry Torokhov Signed-off-by: Rafael J. Wysocki

ACPI / button: remove pointer to old lid_sysfs on unbind

2016-08-02T23:27:20+00:00

When we removed the procfs dir on error or if the driver is unbound, the two variables acpi_lid_dir and acpi_button_dir were not reset. On the next rebind, those static variables were not null and we couldn't re-register the device again. Signed-off-by: Benjamin Tissoires Acked-by: Lv Zheng Signed-off-by: Rafael J. Wysocki

ACPI / button: Add quirks for initial lid state notification

2016-06-22T00:10:17+00:00

Linux userspace (systemd-logind) keeps on rechecking lid state when the lid state is closed. If it failed to update the lid state to open after boot/resume, the system suspending right after the boot/resume could be resulted. Graphics drivers also use the lid notifications to implment MODESET_ON_LID_OPEN option. Before the situation is improved from the userspace and from the graphics driver, users can simply configure ACPI button driver to send initial "open" lid state using button.lid_init_state=open to avoid such kind of issues. And our ultimate target should be making button.lid_init_state=ignore the default behavior. This patch implements the 2 options and keep the old behavior (button.lid_init_state=method). Link: https://lkml.org/2016/3/7/460 Link: https://github.com/systemd/systemd/issues/2087 Signed-off-by: Lv Zheng Signed-off-by: Rafael J. Wysocki

ACPI / button: Refactor functions to eliminate redundant code

2016-06-22T00:10:15+00:00

(Correct a wrong macro usage.) This patch simplies the code by merging some redundant code. No functional changes. Signed-off-by: Lv Zheng Signed-off-by: Rafael J. Wysocki

ACPI / button: Remove initial lid state notification

2016-06-22T00:10:14+00:00

The _LID control method's initial returning value is not reliable. The _LID control method is described to return the "current" lid state. However the word of "current" has ambiguity, many BIOSen return the lid state upon the last lid notification instead of returning the lid state upon the last _LID evaluation. There won't be difference when the _LID control method is evaluated during the runtime, the problem is its initial returning value. When the BIOSen implement this control method with cached value, the initial returning value is likely not reliable. There are simply so many examples retuning "close" as initial lid state (Link 1), sending this state to the userspace causes suspending right after booting/resuming. Since the lid state is implemented by the BIOSen, the kernel lid driver has no idea how it can be correct, this patch stops sending the initial lid state to the userspace to try to avoid sending the wrong lid state to the userspace to trigger such kind of wrong suspending. This actually reverts the following commit introduced for fixing a Novell bug: Commit: 23de5d9ef2a4bbc4f733f58311bcb7cf6239c813 Subject: ACPI: button: send initial lid state after add and resume Link: https://bugzilla.kernel.org/show_bug.cgi?id=89211 Link: https://bugzilla.kernel.org/show_bug.cgi?id=106151 Link: https://bugzilla.kernel.org/show_bug.cgi?id=106941 Link: https://bugzilla.novell.com/show_bug.cgi?id=326814 Signed-off-by: Lv Zheng Signed-off-by: Rafael J. Wysocki

ACPI: Remove FSF mailing addresses

2015-07-08T00:27:32+00:00

There is no need to carry potentially outdated Free Software Foundation mailing address in file headers since the COPYING file includes it. Signed-off-by: Jarkko Nikula Signed-off-by: Rafael J. Wysocki