## page was renamed from Kernel/Reference/fwts/lid
== Firmware Test Suite - lid test ==

This interactive test sanity checks the operation of the ACPI lid switch found on netbooks and laptops.  Several tests are performed:

 * Check the existence of lid switches(s) (in the /proc/acpi/button/lid/*/info fields)
 * Request lid closed and opened and check if an ACPI button/lid event occurs
 * Check for System Control Interrupt(s) and General Purpose Event(s) to occur.

See section 4.7.4.2.1 "Lid Switch" of the ACPI specification for more details.

=== Examples: ===

{{{
fwts lid - 
}}}

..runs the test on your machine and dumps the output to stdout. This test requires user interaction.

== Explanation of test results ==

Certain test results may require a little more explanation. This section will try and give some context to specific test failures.

||Error ID||Explanation||
||No``Lid``Path||/proc/acpi/button/lid does not exist, either because /proc is not mounted or the APCI button driver could not find the button HID PNP0C0D.||
||No``Lid``Switch||Could not detect any /proc/acpi/button/lid/*/info fields.||
||Lid``Not``Open||Could not detect that the lid was open via the /proc/acpi/button/lid/*/info field.||
||No``Lid``Events||No ACPI lid events detected. This could indicate either that either the ACPI SCI interrupt or the button GPE are failing to be triggered, or perhaps the acpid is not picking these events up from the kernel.||
||No``SCI``Interrupts||No SCI interrupts detected - one should get at least one per lid event, failure probably indicates a hardware or wiring fault.||
||No``NoGPE``Interrupts||No General Purpose Events detected.  A GPE is associated with the lid, and should occur. If it a SCI occurs and no GPE occurs then this is some kind of GPE configuration/routing issue.||
||No``Lid``State||Could not detect an ACPI lid state transition.||