diff options
| -rw-r--r-- | arch/i386/kernel/tsc.c | 20 | ||||
| -rw-r--r-- | include/asm-i386/msr.h | 3 |
2 files changed, 23 insertions, 0 deletions
diff --git a/arch/i386/kernel/tsc.c b/arch/i386/kernel/tsc.c index 22931d24027c..3082a418635c 100644 --- a/arch/i386/kernel/tsc.c +++ b/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/include/asm-i386/msr.h b/include/asm-i386/msr.h index 609a3899475c..6db40d0583f1 100644 --- a/include/asm-i386/msr.h +++ b/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 */ |