libata-acpi: improve dock event handling
libata-acpi: improve dock event handling

Improve ACPI hotplug handling such that dock event is handled properly.

* Register handlers for dock events.

* Directly detach device on EJECT_REQUEST instead of signaling hotplug
  event.  This prevents libata from accessing severed controller
  and/or device.

* While at it, use named constants for ACPI events and move uevent
  signaling inside host lock.

Original patch and testing by Holger Macht.

Signed-off-by: Tejun Heo <ccfba69985e72fbcd9ba8bbb6db43d42971ad06d@gmail.com>
Cc: Holger Macht <fc1231ee8ac5775cc29edf7ec28735f6f6ebcc6c@suse.de>
Signed-off-by: Jeff Garzik <f3e731dfa293c7a83119d8aacfa41b5d2d780be9@garzik.org>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs