This is an old suspend/resume lockup fix:
commit 2780cc4660e1
Author: Len Brown <len.brown@intel.com>
Date: Thu Dec 23 13:43:30 2004 -0500
[ACPI] Fix suspend/resume lockup issue
by leaving Bus Master Arbitration enabled.
The ACPI spec mandates it be disabled only for C3.
http://bugzilla.kernel.org/show_bug.cgi?id=3599
Signed-off-by: David Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
The bug snuck back in in commit 2feec47d4c (ACPICA: ACPI 5: Support
for new FADT SleepStatus, SleepControl registers, 2012-02-14),
presumably by copy/pasting a copy of the code without that fix for the
legacy case.
On affected machines, after that commit, the machine locks up hard on
resume from suspend. The same fix as seven years ago still works.
Addresses <https://bugzilla.kernel.org/show_bug.cgi?id=43641>.
Reported-bisected-and-tested-by: Octavio Alvarez <alvarezp@alvarezp.com>
Reported-by: Adrian Knoth <adi@drcomp.erfurt.thur.de>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
dc332fdf9f