From 1ddeb7b86737d0ec23b230d4df0b4663646a9442 Mon Sep 17 00:00:00 2001
From: Zhang Rui <rui.zhang@intel.com>
Date: Thu, 27 Feb 2014 11:37:15 +0800
Subject: ACPI / resources: ignore invalid ACPI device resources

commit b355cee88e3b1a193f0e9a81db810f6f83ad728b upstream.

ACPI table may export resource entry with 0 length.
But the current code interprets this kind of resource in a wrong way.
It will create a resource structure with
res->end = acpi_resource->start + acpi_resource->len - 1;

This patch fixes a problem on my machine that a platform device fails
to be created because one of its ACPI IO resource entry (start = 0,
end = 0, length = 0) is translated into a generic resource with
start = 0, end = 0xffffffff.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index b7201fc..0bdacc5 100644
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -77,18 +77,24 @@ bool acpi_dev_resource_memory(struct acpi_resource *ares, struct resource *res)
 	switch (ares->type) {
 	case ACPI_RESOURCE_TYPE_MEMORY24:
 		memory24 = &ares->data.memory24;
+		if (!memory24->address_length)
+			return false;
 		acpi_dev_get_memresource(res, memory24->minimum,
 					 memory24->address_length,
 					 memory24->write_protect);
 		break;
 	case ACPI_RESOURCE_TYPE_MEMORY32:
 		memory32 = &ares->data.memory32;
+		if (!memory32->address_length)
+			return false;
 		acpi_dev_get_memresource(res, memory32->minimum,
 					 memory32->address_length,
 					 memory32->write_protect);
 		break;
 	case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
 		fixed_memory32 = &ares->data.fixed_memory32;
+		if (!fixed_memory32->address_length)
+			return false;
 		acpi_dev_get_memresource(res, fixed_memory32->address,
 					 fixed_memory32->address_length,
 					 fixed_memory32->write_protect);
@@ -144,12 +150,16 @@ bool acpi_dev_resource_io(struct acpi_resource *ares, struct resource *res)
 	switch (ares->type) {
 	case ACPI_RESOURCE_TYPE_IO:
 		io = &ares->data.io;
+		if (!io->address_length)
+			return false;
 		acpi_dev_get_ioresource(res, io->minimum,
 					io->address_length,
 					io->io_decode);
 		break;
 	case ACPI_RESOURCE_TYPE_FIXED_IO:
 		fixed_io = &ares->data.fixed_io;
+		if (!fixed_io->address_length)
+			return false;
 		acpi_dev_get_ioresource(res, fixed_io->address,
 					fixed_io->address_length,
 					ACPI_DECODE_10);
-- 
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