From 949a61372b94d7ea4ad0842a6bb5fc1c5d16a633 Mon Sep 17 00:00:00 2001
From: Marcelo Tosatti <marcelo@kvack.org>
Date: Fri, 16 Feb 2007 01:27:44 -0800
Subject: [PATCH] --- yaml --- r: 48575 b: refs/heads/master c:
 07190a08eef3666a8687070226c8d403c1d548b7 h: refs/heads/master i:   48573:
 ac76c1b15de4cb44f51dd00bf95a1cdaebc0c37a   48571:
 9c4054985795513487c9f32ada88f18b4fc268ab   48567:
 1766a4b4650bdcb4fbbaf446fe042dd767b741a2   48559:
 024e398995ac26fa8d5329b566025f73b841d22e   48543:
 a64730ddafcc9d7063f5aac3c18822657b9dcee4   48511:
 dfc84b3125fe9157da1123aa2680ca670e5c0628 v: v3

---
 [refs]                       |  2 +-
 trunk/arch/i386/kernel/tsc.c | 20 ++++++++++++++++++++
 trunk/include/asm-i386/msr.h |  3 +++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 6ec26e953a6e..f87c753bcbbc 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 5d8b34fdcb384161552d01ee8f34af5ff11f9684
+refs/heads/master: 07190a08eef3666a8687070226c8d403c1d548b7
diff --git a/trunk/arch/i386/kernel/tsc.c b/trunk/arch/i386/kernel/tsc.c
index 22931d24027c..3082a418635c 100644
--- a/trunk/arch/i386/kernel/tsc.c
+++ b/trunk/arch/i386/kernel/tsc.c
@@ -364,6 +364,25 @@ __cpuinit int unsynchronized_tsc(void)
 	return tsc_unstable;
 }
 
+/*
+ * Geode_LX - the OLPC CPU has a possibly a very reliable TSC
+ */
+#ifdef CONFIG_MGEODE_LX
+/* RTSC counts during suspend */
+#define RTSC_SUSP 0x100
+
+static void __init check_geode_tsc_reliable(void)
+{
+	unsigned long val;
+
+	rdmsrl(MSR_GEODE_BUSCONT_CONF0, val);
+	if ((val & RTSC_SUSP))
+		clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY;
+}
+#else
+static inline void check_geode_tsc_reliable(void) { }
+#endif
+
 static int __init init_tsc_clocksource(void)
 {
 
@@ -372,6 +391,7 @@ static int __init init_tsc_clocksource(void)
 		dmi_check_system(bad_tsc_dmi_table);
 
 		unsynchronized_tsc();
+		check_geode_tsc_reliable();
 		current_tsc_khz = tsc_khz;
 		clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
 							clocksource_tsc.shift);
diff --git a/trunk/include/asm-i386/msr.h b/trunk/include/asm-i386/msr.h
index 609a3899475c..6db40d0583f1 100644
--- a/trunk/include/asm-i386/msr.h
+++ b/trunk/include/asm-i386/msr.h
@@ -307,4 +307,7 @@ static inline void wrmsrl (unsigned long msr, unsigned long long val)
 #define MSR_CORE_PERF_GLOBAL_CTRL	0x38f
 #define MSR_CORE_PERF_GLOBAL_OVF_CTRL	0x390
 
+/* Geode defined MSRs */
+#define MSR_GEODE_BUSCONT_CONF0         0x1900
+
 #endif /* __ASM_MSR_H */