linux-imx

ACPI / AC: Add sleep quirk for Thinkpad e530

The Thinkpad e530's BIOS notifies the AC device first and then
sleeps for certain amount of time before doing real work in the
EC event handler (_Qxx):

 Method (_Q27, 0, NotSerialized)
 {
       Notify (AC, 0x80)
       Sleep (0x03E8)
       Store (Zero, PWRS)
       PNOT ()
 }

This causes the AC driver to report an outdated AC state to user
space, because it reads the state information from the device while
the EC handler is sleeping.

Introduce a quirk to cause the AC driver to wait in acpi_ac_notify()
before calling acpi_ac_get_state() on systems known to have this
problem and add Thinkpad e530 to the list of quirky machines (with
a 1s delay which has been verified to be sufficient for that
machine).

[rjw: Changelog]
References: https://bugzilla.kernel.org/show_bug.cgi?id=45221
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>