ACPI / resources: only reject zero length resources based at address zero

commit 867f9d463b upstream.

The recently merged change (in v3.14-rc6) to ACPI resource detection
(below) causes all zero length ACPI resources to be elided from the
table:

  commit b355cee88e
  Author: Zhang Rui <rui.zhang@intel.com>
  Date:   Thu Feb 27 11:37:15 2014 +0800

    ACPI / resources: ignore invalid ACPI device resources

This change has caused a regression in (at least) serial port detection
for a number of machines (see LP#1313981 [1]).  These seem to represent
their IO regions (presumably incorrectly) as a zero length region.
Reverting the above commit restores these serial devices.

Only elide zero length resources which lie at address 0.

Fixes: b355cee88e (ACPI / resources: ignore invalid ACPI device resources)
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Andy Whitcroft 2014-06-19 11:19:16 +01:00 • committed by Greg Kroah-Hartman
commit a972b86e08