[Bug 594837] [NEW] Lucid SRU: Intel Core i3/i5/i7 hang on resume from suspend (SCI_EN)

[Kamal Mostafa]

Public bug reported:

Intel Core i3/i5/i7 machines hang on resume from suspend due to the
SCI_EN bit being left unset by the BIOS.

*** This bug relates ONLY to systems with Intel Core i3/i5/i7 CPU's ***

IMPACT:
System hang on resume is a major malfunction.

HOW ADDRESSED:
In Lucid, this is currently addressed for certain specific machines via a quirk table listing machines for which SCI_EN gets forcibly set on resume (see bug 553498 which enables it for "Dell Studio 155x" models).  The following patch from upstream needs to be applied to Lucid to address the problem for all machines.

PATCH:
(from 2.6.35-rc1; appears in Maverick already)
commit b6dacf63e9fb2e7a1369843d6cef332f76fca6a3
Author: Matthew Garrett <mjg at redhat.com>
Date: Tue May 11 13:49:25 2010 -0400

    ACPI: Unconditionally set SCI_EN on resume

This patch applies cleanly to Lucid (2.6.32-23.37).

TEST CASE:
Intel Core i3/i5/i7 machine:  Suspend the machine via any method, then wake it.  On resume, system powers up but hangs immediately (Dell Studio 155x gets black screen, fan stuck on).

REGRESSION POTENTIAL:
As has been discussed on LKML and linux-acpi, setting SCI_EN is a violation of the ACPI spec, but it (a) works, and (b) follows the example of another major operating system.  There exists a potential that this method will cause problems for some machine but none are known at this time.

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New

-- 
Lucid SRU: Intel Core i3/i5/i7 hang on resume from suspend (SCI_EN)
https://bugs.launchpad.net/bugs/594837
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