---

yaml
---
r: 80390
b: refs/heads/master
c: e6c4dc6
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 45078cb5e2fb5a0e55c373755ed45b43d901f9e4
+refs/heads/master: e6c4dc6c36b01d33a2e0c8a89828d8dd44fb4c1b

trunk/Documentation/kernel-parameters.txt

@@ -1092,6 +1092,11 @@ and is between 256 and 4096 characters. It is defined in the file
 			Multi-Function General Purpose Timers on AMD Geode
 			platforms.
 
+	mfgptfix	[X86-32] Fix MFGPT timers on AMD Geode platforms when
+			the BIOS has incorrectly applied a workaround. TinyBIOS
+			version 0.98 is known to be affected, 0.99 fixes the
+			problem by letting the user disable the workaround.
+
 	mga=		[HW,DRM]
 
 	mousedev.tap_time=

trunk/arch/x86/kernel/mfgpt_32.c

@@ -63,6 +63,21 @@ static int __init mfgpt_disable(char *s)
 }
 __setup("nomfgpt", mfgpt_disable);
 
+/* Reset the MFGPT timers. This is required by some broken BIOSes which already
+ * do the same and leave the system in an unstable state. TinyBIOS 0.98 is
+ * affected at least (0.99 is OK with MFGPT workaround left to off).
+ */
+static int __init mfgpt_fix(char *s)
+{
+	u32 val, dummy;
+
+	/* The following udocumented bit resets the MFGPT timers */
+	val = 0xFF; dummy = 0;
+	wrmsr(0x5140002B, val, dummy);
+	return 1;
+}
+__setup("mfgptfix", mfgpt_fix);
+
 /*
  * Check whether any MFGPTs are available for the kernel to use.  In most
  * cases, firmware that uses AMD's VSA code will claim all timers during