[PATCH 2.6.31.stable] ACPI: Clarify resource conflict message

[Len Brown <lenb@kernel.org>]

From: Jean Delvare <jdelvare@suse.de>

upstream 14f03343ad1080c2fea29ab2c13f05b976c4584e

>From 14f03343ad1080c2fea29ab2c13f05b976c4584e Mon Sep 17 00:00:00 2001
From: Jean Delvare <jdelvare@suse.de>
Date: Tue, 8 Sep 2009 15:31:46 +0200
Subject: [PATCH] ACPI: Clarify resource conflict message
X-Patchwork-Hint: ignore

The message "ACPI: Device needs an ACPI driver" is misleading. The
device _may_ need an ACPI driver, if the BIOS implemented a custom
API for the device in question (which, AFAIK, can't be checked.) If
not, then either a generic ACPI driver may be used (for example
"thermal"), or nothing can be done (other than a white list).

I propose to reword the message to:

ACPI: If an ACPI driver is available for this device, you should use
it instead of the native driver

which I think is more correct. Comments and suggestions welcome.

I also added a message warning about possible problems and system
instability when users pass acpi_enforce_resources=lax, as suggested
by Len.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Thomas Renninger <trenn@suse.de>
Cc: Alan Jenkins <sourcejedi.lkml@googlemail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
---
 drivers/acpi/osl.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

Index: linux-2.6.31.y/drivers/acpi/osl.c
===================================================================
--- linux-2.6.31.y.orig/drivers/acpi/osl.c
+++ linux-2.6.31.y/drivers/acpi/osl.c
@@ -1182,7 +1182,13 @@ int acpi_check_resource_conflict(struct 
 			       res_list_elem->name,
 			       (long long) res_list_elem->start,
 			       (long long) res_list_elem->end);
-			printk(KERN_INFO "ACPI: Device needs an ACPI driver\n");
+			if (acpi_enforce_resources == ENFORCE_RESOURCES_LAX)
+				printk(KERN_NOTICE "ACPI: This conflict may"
+				       " cause random problems and system"
+				       " instability\n");
+			printk(KERN_INFO "ACPI: If an ACPI driver is available"
+			       " for this device, you should use it instead of"
+			       " the native driver\n");
 		}
 		if (acpi_enforce_resources == ENFORCE_RESOURCES_STRICT)
 			return -EBUSY;