From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 19 Oct 2007 18:35:02 +0000 (+0200)
Subject: x86: add force_hpet boot option
X-Git-Tag: v2.6.24-rc1~132^2~20
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b17530bda22e7ffbf08f7a8a50743256b1672f6a;p=linux-2.6

x86: add force_hpet boot option

add force_hpet boot option.

(this will be useful to make the forced-enable quirks depend on.)

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 189df0bcab..c6859b94aa 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -431,8 +431,10 @@ and is between 256 and 4096 characters. It is defined in the file
 			over the 8254 in addition to over the IO-APIC. The
 			kernel tries to set a sensible default.
 
-	hpet=		[X86-32,HPET] option to disable HPET and use PIT.
-			Format: disable
+	hpet=		[X86-32,HPET] option to control HPET usage
+			Format: { enable (default) | disable | force }
+			disable: disable HPET and use PIT instead
+			force: allow force enabled of undocumented chips (ICH4, VIA)
 
 	com20020=	[HW,NET] ARCnet - COM20020 chipset
 			Format:
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index f8367074da..22d8f00c80 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -69,12 +69,15 @@ static inline void hpet_clear_mapping(void)
  * HPET command line enable / disable
  */
 static int boot_hpet_disable;
+int hpet_force_user;
 
 static int __init hpet_setup(char* str)
 {
 	if (str) {
 		if (!strncmp("disable", str, 7))
 			boot_hpet_disable = 1;
+		if (!strncmp("force", str, 5))
+			hpet_force_user = 1;
 	}
 	return 1;
 }
diff --git a/include/asm-x86/hpet.h b/include/asm-x86/hpet.h
index d4ab6db050..4f51519fc1 100644
--- a/include/asm-x86/hpet.h
+++ b/include/asm-x86/hpet.h
@@ -64,6 +64,7 @@
 /* hpet memory map physical address */
 extern unsigned long hpet_address;
 extern unsigned long force_hpet_address;
+extern int hpet_force_user;
 extern int is_hpet_enabled(void);
 extern int hpet_enable(void);
 extern unsigned long hpet_readl(unsigned long a);