Change in coreboot[master]: arch/x86: Write ACPI DBG2 table only if the device has been enabled

[Mario Scheithauer (Code Review)]

Mario Scheithauer has uploaded this change for review. ( https://review.coreboot.org/22552

Change subject: arch/x86: Write ACPI DBG2 table only if the device has been enabled
......................................................................

arch/x86: Write ACPI DBG2 table only if the device has been enabled

The commit https://review.coreboot.org/#/c/22452/ causes a crash on the
mainboard mc_apl1. On this mainboard all internal SOC UARTs in the
devicetree are switched off. As a result, no resources are allocated to
the UARTs. The function find_resource() expects an existing resource.
Otherwise, the CPU will stop. It should therefore not only be queried
whether a device is present, but also whether it has been enabled.

Change-Id: I56ce44ae0cf77916fcb640f79fb8944fe33177cd
Signed-off-by: Mario Scheithauer 
---
M src/arch/x86/acpi.c
1 file changed, 5 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/52/22552/1

diff --git a/src/arch/x86/acpi.c b/src/arch/x86/acpi.c
index 56f6408..5a29ac1 100644
--- a/src/arch/x86/acpi.c
+++ b/src/arch/x86/acpi.c
@@ -8,7 +8,7 @@
  * Copyright (C) 2005-2009 coresystems GmbH
  * Copyright (C) 2015 Timothy Pearson ,
  * Raptor Engineering
- * Copyright (C) 2016 Siemens AG
+ * Copyright (C) 2016-2017 Siemens AG
  *
  * ACPI FADT, FACS, and DSDT table support added by
  * Nick Barker , and those portions
@@ -734,6 +734,10 @@
    	printk(BIOS_ERR, "%s: Device not found\n", __func__);
    	return current;
    }
+	if (!dev->enabled) {
+		printk(BIOS_ERR, "%s: Device not enabled\n", __func__);
+		return current;
+	}
    res = find_resource(dev, PCI_BASE_ADDRESS_0);
    if (!res) {
    	printk(BIOS_ERR, "%s: Unable to find resource for %s\n",