[3.16.y-ckt stable] Patch "ACPI / init: Fix the ordering of acpi_reserve_resources()" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    ACPI / init: Fix the ordering of acpi_reserve_resources()

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt13.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 0dc093f17a45aac8b10de6c7b04f71c6a5c88d65 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki at intel.com>
Date: Thu, 7 May 2015 21:19:39 +0200
Subject: ACPI / init: Fix the ordering of acpi_reserve_resources()

commit b9a5e5e18fbf223502c0b2264c15024e393da928 upstream.

Since acpi_reserve_resources() is defined as a device_initcall(),
there's no guarantee that it will be executed in the right order
with respect to the rest of the ACPI initialization code.  On some
systems this leads to breakage if, for example, the address range
that should be reserved for the ACPI fixed registers is given to
the PCI host bridge instead if the race is won by the wrong code
path.

Fix this by turning acpi_reserve_resources() into a void function
and calling it directly from within the ACPI initialization sequence.

Reported-and-tested-by: George McCollister <george.mccollister at gmail.com>
Link: http://marc.info/?t=143092384600002&r=1&w=2
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/acpi/osl.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index bad25b070fe0..1b2d872c7398 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -172,7 +172,7 @@ static void __init acpi_request_region (struct acpi_generic_address *gas,
 		request_mem_region(addr, length, desc);
 }

-static int __init acpi_reserve_resources(void)
+static void __init acpi_reserve_resources(void)
 {
 	acpi_request_region(&acpi_gbl_FADT.xpm1a_event_block, acpi_gbl_FADT.pm1_event_length,
 		"ACPI PM1a_EVT_BLK");
@@ -201,10 +201,7 @@ static int __init acpi_reserve_resources(void)
 	if (!(acpi_gbl_FADT.gpe1_block_length & 0x1))
 		acpi_request_region(&acpi_gbl_FADT.xgpe1_block,
 			       acpi_gbl_FADT.gpe1_block_length, "ACPI GPE1_BLK");
-
-	return 0;
 }
-device_initcall(acpi_reserve_resources);

 void acpi_os_printf(const char *fmt, ...)
 {
@@ -1827,6 +1824,7 @@ acpi_status __init acpi_os_initialize(void)

 acpi_status __init acpi_os_initialize1(void)
 {
+	acpi_reserve_resources();
 	kacpid_wq = alloc_workqueue("kacpid", 0, 1);
 	kacpi_notify_wq = alloc_workqueue("kacpi_notify", 0, 1);
 	kacpi_hotplug_wq = alloc_ordered_workqueue("kacpi_hotplug", 0);