From 6dcfb3e35072add4df4cd79c8ec87d7b3d449489 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 15 Nov 2007 21:41:50 -0500
Subject: [PATCH] --- yaml --- r: 73901 b: refs/heads/master c:
 f4df73c2914a49bf6a55896aaecb0563c955e167 h: refs/heads/master i:   73899:
 a5740a0a0276f9ec3c5ae428fdef68e38e12b2e8 v: v3

---
 [refs]                            |  2 +-
 trunk/arch/x86/kernel/acpi/boot.c | 32 +++++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 47784ed9828c..dc81867270d8 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: bbbd99955bfe84c9ae63f51db946a7bcd21f48be
+refs/heads/master: f4df73c2914a49bf6a55896aaecb0563c955e167
diff --git a/trunk/arch/x86/kernel/acpi/boot.c b/trunk/arch/x86/kernel/acpi/boot.c
index 289247d974c6..0ca27c7b0e8d 100644
--- a/trunk/arch/x86/kernel/acpi/boot.c
+++ b/trunk/arch/x86/kernel/acpi/boot.c
@@ -637,6 +637,38 @@ static int __init acpi_parse_hpet(struct acpi_table_header *table)
 	}
 
 	hpet_address = hpet_tbl->address.address;
+
+	/*
+	 * Some broken BIOSes advertise HPET at 0x0. We really do not
+	 * want to allocate a resource there.
+	 */
+	if (!hpet_address) {
+		printk(KERN_WARNING PREFIX
+		       "HPET id: %#x base: %#lx is invalid\n",
+		       hpet_tbl->id, hpet_address);
+		return 0;
+	}
+#ifdef CONFIG_X86_64
+	/*
+	 * Some even more broken BIOSes advertise HPET at
+	 * 0xfed0000000000000 instead of 0xfed00000. Fix it up and add
+	 * some noise:
+	 */
+	if (hpet_address == 0xfed0000000000000UL) {
+		if (!hpet_force_user) {
+			printk(KERN_WARNING PREFIX "HPET id: %#x "
+			       "base: 0xfed0000000000000 is bogus\n "
+			       "try hpet=force on the kernel command line to "
+			       "fix it up to 0xfed00000.\n", hpet_tbl->id);
+			hpet_address = 0;
+			return 0;
+		}
+		printk(KERN_WARNING PREFIX
+		       "HPET id: %#x base: 0xfed0000000000000 fixed up "
+		       "to 0xfed00000.\n", hpet_tbl->id);
+		hpet_address >>= 32;
+	}
+#endif
 	printk(KERN_INFO PREFIX "HPET id: %#x base: %#lx\n",
 	       hpet_tbl->id, hpet_address);